AMERICAN
PALEONTOLOGIST
16, NUMBER 2
SUMMER 2008
VOLUME
A MAGAZINE OF EARTH SCIENCE PUBLISHED BY THE PALEONTOLOGICAL RESEARCH INSTITUTION AND ITS MUSEUM OF THE EARTH
Dinosaur Eggs
North America
through
time:
A PALEONTOLOGICAL HISTORY OF OUR CONTINENT
Lynne M. Clos
What part has North America played in the history of
life? How did our continent come to be, and how has
it changed over time? What was it like during past
ages, and what plants and animals lived here? Where
can fossils from each age be found? And where are
there public preserves where you can view the fossils
in place?
• Eighteen chapters, beginning with the Precambrian,
and covering each time Period of the Paleozoic and
Mesozoic Eras, and each Epoch of the Cenozoic
• Twenty-five stunning paleoenvironmental
reconstructions, all in full color
• Over 200 color photographs of fossils
• Covers North America from the Atlantic to the
Pacific, and from the Panama Canal to the Arctic
Ocean
Clothbound, 8” x 10”
296 pages, full color throughout
ISBN 978-0-9724416-4-3
$35.00 + free shipping
autographed copies available
on request
Fossil News
1185 Claremont Dr.
Boulder, Colorado 80305
www.fossilnews.com
phone orders (303) 499-5337, afternoons &
evenings only, mountain time, please
FROM THE EDITOR
A New Look for AP
By Paula Mikkelsen
Sometimes subtle changes make all the difference. You might
notice (or maybe you will now) that this issue of American
Paleontologist is slightly different from last time. Although we
have been very proud of the appearance of issues in the last
few years, conversations that we have had of late with readers, staff members (especially PRI’s energetic new Marketing
Director, Billy Kepner), and others in “the biz” have pointed
out that our magazine doesn’t “feel” like a magazine. More
often than we expected, entirely independent contacts said
the same thing – “It feels like an annual report.” As a result,
American Paleontologist might not be the one that you grab
off the coffee table to stash in your backpack, or roll up in
your back pocket to read on the treadmill at the gym. It also
apparently falls into that category of publications that folks
enjoy reading, but feel guilty about tossing when they’re done
– so it lands in an ever-accumulating (and perhaps slightly irritating) pile of journals that one has to find a place for in the
already bulging bookcase. Somehow, it’s appearance resists
recycling, and although that never bothered me personally as
an editor or as a natural historian (I have always kept AP issues anyway), perhaps that characteristic bothers some readers, most importantly our valued members.
But what on Earth does “doesn’t feel like a magazine”
mean? How do we fix that? A careful survey of popular
magazines, including respected lay-science titles like Natural
History and Smithsonian, showed us that size really does matter! These successful magazines measure from edge to edge
slightly less than our admittedly academic 8-1/2 by 11 inch
format. So, okay, if that’s important, we can do that. If you
take the trouble to drag out a ruler and measure, you will see
that our new pages measure 8-1/8 by 10-1/2 inches.
Paper quality is also important. Again, comparison with
other magazines quickly led to the conclusion that our customary paper stock was too heavy and too white. Well, isn’t
really good quality, white paper a good thing? Apparently too
good, at least in the world of magazines suitable for the treadmill or backpack. So you will notice that our paper is now
thinner and (as a result) slightly less bright-white.
Better? Time will tell, but we think so! These measures
are part of a plan to increase the circulation and readership of
American Paleontologist, and thus the enjoyment and appreciation of paleontology, by making it available on newsstands,
first in the region and later (we hope) nationwide. Remember
too that in addition to being a membership benefit, AP is
available by annual subscription to those who are interested
in fossils, evolution, climate change, and the other paleonews-y things that we offer, but who live too far from Ithaca
to take regular advantage of the benefits for local members,
such as unlimited admission to Museum of the Earth, invitations to special events, and discounts on programs and
purchases at the Museum Store. Rest assured that AP will
continue for the forseeable future as a member benefit. We
are just ready to reach out to a larger audience – and the
subtle format changes that we have made to become more
“magazine-like” are part of this plan.
Please allow me to brag a bit about other features of this
issue. It is another in a series – like Dinosaurs in Pop Culture (Winter 2007) and The Fossil Fish of Green River (Spring
2008) – themed to accompany a temporary exhibition at
Museum of the Earth. This is not to say that we have decided
to always mirror our exhibition programming – it is just a
reflection of how exciting the subjects of our exhibitions have
been lately! The exhibition “Hatching the Past: Dinosaur Eggs
and Babies” runs at MotE from 21 June through 21 September 2008. It is the creation of professional fossil preparators
Florence and Charles Magovern of Boulder, Colorado, who
have also written one of the articles in this issue. It tells the
story of “Baby Louie,” discovered by Charles in 1993, and
which (who?) is still the most complete known specimen of a
baby dinosaur. A cast of Baby Louie’s bones and a feathered
reconstruction are part of the exhibit. This issue also includes
an article from Professor Connie Soja who, together with her
students at Colgate University, have conducted experiments
to shed light on the environmental conditions that have allowed the fossilized preservation of seemingly-fragile dinosaur eggs.
Our regular features are also growing. Adding to the always-wonderful regular columns by John Catalani and Peter
Dodson, we are pleased to introduce a new column to the
pages of American Paleontologist. “The Nature of Science” by
new PRI Director of Teacher Programs Richard Kissel will
explore paleontological subjects from the unique perspectives of our educational staff. In this issue, Richard writes
appropriately about the evolution of the amniotic egg, an
enormously important adaptation that allowed animals to
venture away from the water so essential for the survival of
their ancestors. (Look also for Richard’s charming original
cartoons!) And always-inventive PRI Director of Public Programs Samantha Sands has created another fun-filled issue of
Fossil Stuff to delight our “egg-centric” younger readers.
Like all things biologic, American Paleontologist is evolving, in part in response to environment (the magazine market) and in part by chance (through talented staff and imaginative exhibits). We hope you like our new baby!
Paleontological Research Institution
FOUNDED 1932
BOARD OF TRUSTEES
Officers
President David H. Taube, Lansing, NY
Vice President Priscilla Browning, Ithaca, NY
Secretary Philip Bartels, Riverside, CT
Members
Carolyn Ainslie, Ithaca, NY
John D. Allen, Syracuse, NY
Loren E. Babcock, Columbus, OH
Philip Bartels, Riverside, CT
Larry Baum, Ithaca, NY
Priscilla Browning, Ithaca, NY
Thomas Bruce, Ithaca, NY
James M. Cordes, Ithaca, NY
Harold Craft, Berkshire, NY
Helene Dillard, Ithaca, NY
J. Thomas Dutro, Jr., Washington, DC
Rodney Feldmann, Kent, OH
W. Kent Fuchs, Ithaca, NY
Howard P. Hartnett, Moravia, NY
Teresa Jordan, Ithaca, NY
Patricia H. Kelley, Southport, NC
Stephan Loewentheil, New York, NY
Robert Mackenzie, Trumansburg, NY
James Moore, Rochester, NY
Jeff Over, Geneseo, NY
John Pojeta, Rockville, MD
Philip Proujansky, Ithaca, NY
Phil Reilly, Concord, MA
Mary M. Shuford, Brooklyn, NY
Paul Steiger, Ithaca, NY
David H. Taube, Lansing, NY
Trustees Emeritus
Shirley K. Egan, Aurora, NY
Robert T. Horn, Jr., Ithaca, NY
Harry Lee, Jacksonville, FL
Harry A. Leffingwell, Laguna Beach, CA
Amy McCune, Ithaca, NY
Samuel T. Pees, Meadville, PA
Edward B. Picou, Jr., New Orleans, LA
Constance Soja, Hamilton, NY
James E. Sorauf, Tarpon Springs, FL
John C. Steinmetz, Bloomington, IN
Peter B. Stifel, Easton, MD
William P. S. Ventress, Lexington, OK
Art Waterman, Metarie, LA
Thomas E. Whiteley, Rochester, NY
Staff
Warren D. Allmon, Director
Sarah Anderson, Associate Director of Institutional Advancement
Leon Apgar, Maintenance and Operations Specialist
Sara Auer, Education Programs Manager
Carlyn Buckler, Assistant to Associate Director for Outreach
Sarah Chicone, Director of Exhibits
Sarah Degen, Development Operations Manager
Gregory Dietl, Director of Collections
Brian Gollands, Web Designer
Michael Griswold, Facilities Manager
John Gurche, Artist-in-Residence
Billy Kepner, Director of Marketing
Richard Kissel, Director of Teacher Programs
Andrea Kreuzer, Assistant to the Director
Tamsin Leavy, Assistant Museum Operations Manager
Michael Lucas, Associate Director for Administration
Paula M. Mikkelsen, Director of Publications
Sam Moody, Museum Operations Manager/Volunteer Coordinator
Judith Nagel-Myers, Collections Database Manager
Alicia Reynolds, Director of Museum Operations
Rob Ross, Associate Director for Outreach
Samantha Sands, Director of Public Programs
AMERICAN
PALEONTOLOGIST
VOL.
16, NO. 2, SUMMER 2008
Paula M. Mikkelsen, Editor
Warren D. Allmon, Director
Other Contributors
Nan Crystal Arens
John A. Catalani
Peter Dodson
Susan j. Hewitt
Elizabeth Humbert
Richard A. Kissel
Christopher A. McRoberts
Charlie and Florence Magovern
Sam Moody
Samantha Sands
Ursula Smith
Constance M. Soja
On the cover: Colgate University’s Oviraptor dinosaur egg,
one of the first complete dinosaur eggs known to science
(see article beginning on page 19). Photograph from Colgate
Viewbook, 2001, p. 16.
American Paleontologist is published quarterly (Spring, Summer, Fall, Winter) for its members by the Paleontological Research Institution (PRI), 1259 Trumansburg
Road, Ithaca, New York 14850 USA, Tel. (607) 273-6623, Fax (607) 273-6620. Individual membership is $35.00 per year, including American Paleontologist subscription. Individual subscriptions are also available for $30 per year. Advertising information is available on request by calling PRI ext. 20 or by emailing publications@
museumoftheearth.org. ISSN 1066-8772. We are not responsible for return of or response to unsolicited manuscripts. Information about PRI and the Museum of the Earth
is available on the worldwide web at http://www.priweb.org and www.museumoftheearth.org. Printed on recycled paper by Arnold Printing, Ithaca, New York.
© 2008 Paleontological Research Institution.
AMERICAN
PALEONTOLOGIST
A MAGAZINE OF EARTH SCIENCE PUBLISHED BY THE PALEONTOLOGICAL RESEARCH INSTITUTION AND ITS MUSEUM OF THE EARTH
VOLUME
16, NUMBER 2, SUMMER 2008
IN THIS ISSUE
FEATURE ARTICLES
Dinosaur Egg Detectives: Cracking the Case
16
By Charlie and Florence Magovern
.
Unscrambling Dinosaur Eggs
21
By Constance M. Soja
.
SUMMER SPECIAL
Fossils on the Beach
12
by Susan J. Hewitt
.
FOCUS ON EDUCATION
Climate Change 101 – Parts 3 and 4
6
by Elizabeth Humbert
.
From the Editor
At the Museum of the Earth
Briefly Noted books of interest
Paleonews
1
4
8
10
Fossil Focus: Rudist Bivalves
15
by Ursula Smith
.
Dodson on Dinosaurs: Paleontology Done Right - Mejungasaurus crenatissimus
26
by Peter Dodson
.
16
An Amateur’s Perspective: Explosions of Biodiversity
30
by John A. Catalani
.
The Nature of Science: The Egg, the Chicken, and the 300 Million Years in Between
35
by Richard A. Kissel
.
Book reviews:
Principles Updated, by Christopher A. McRoberts
And Then There Was One, by Nan Crystal Arens
38
41
12
AT T H E M U S E U M O F T H E E A RT H
and the Paleontological Research Institution
PRI Director Allmon Appointed by Cornell
Tom Lovejoy Speaks for Earth Day
Warren Allmon, Director of
PRI and its Museum of the
Earth has been named the
first Hunter R. Rawlings III
Professor of Paleontology at
Cornell University. Allmon
has been Director of PRI
since 1992, and has supervised graduate students
and taught various courses
at CU during most of that
time. His major research
interest is the ecology of the
origin and maintenance of
biological diversity and the application of the geological record to the study of these problems.
World-renowned environmentalist
Thomas E. Lovejoy III, president
of the Heinz Center for Science,
Economics and the Environment,
spoke at Museum of the Earth on
March 18 on “Climate Change:
Prospects for Nature.” In the
words of Director Warren Allmon,
Lovejoy’s “unique blend of science
and nature” drew a large crowd.
His presentation focused on global climate change and the
impacts that are already being felt around the world. Lovejoy
is also chief biodiversity advisor to World Bank, senior advisor to the president of the United Nations Foundation, and
founder of the television series Nature. He is credited with
coining the term “biological diversity” in 1980.
New Staff Members
Thanks in part to new
programming through
grants aquired last
fall, we welcome these
new staff members.
All interesting people
whom you can meet
at your next Museum
of the Earth event!
Sara Auer is Educational Programs Manager, responsible for
group programs and
tours at the Museum
of the Earth and out
in the local community. Sara has a Masters
degree in volcanology
and geochemistry and
a certificate in Museum Studies from the
University of Oregon.
She is enthralled by
the volcanoes of the
‘Ring of Fire’ from her
Masters fieldwork and
is excited to add yet
another area of expertise to the PRI family.
Richard Kissel is Director of Teacher Programs
and will be writing new
volumes of our TeacherFriendly Guides to Geology. He comes to us via
The Field Museum in
Chicago where he was
primary scientific advisor on their “Evolving Planet” exhibition,
then a program leader
for various educational
programs. His passion
is Paleozoic tetrapods
and he is completing
his PhD on the evolution of terrestrial ecosystems from University
of Toronto.
4 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
Tamsin Leavy is Museum Operations Manager in addition to
working in the Museum
of the Earth store. Before taking this position,
she served as a volunteer
and intern at the Museum. She comes to us
from New Jersey with a
geography and ancient
history teaching background, plus two years
field experience in archaeology. Tamsin plans
on joining the Peace
Corps in eastern Europe
this fall, setting up educational programs for
young women.
Brian Gollands is Web
Designer for the Bivalve
Assembling the Tree of
Life (“BivAToL”) grant
– see http://www.bivatol.
org. He has a Masters
degree in entomology
from Cornell University
and 15 years of experience in web production
and other IT functions,
including outreach. He
comes to PRI via Boyce
Thompson Institute for
Plant Research. He is
a long-time resident of
Ithaca and has young
step-grandchildren who
are very excited about
science and nature.
AT T H E M U S E U M O F T H E E A RT H
and the Paleontological Research Institution
PRI Trilobite to be Showcased at Colgate
Colgate University in Hamilton, New York, is building a
new science building and a balustrade will include fossil images etched in glass. One of the
images is taken from the book
Trilobites of New York (Cornell University Press, 2002) by
PRI Trustee Emeritus Thomas
E. Whiteley (left) (along with
Gerald J. Kloc and Carlton E.
Brett). The specimen depicted
– Eldredgeops rana, from Genesee County, Middle Devonian
– was donated by Dr. Whiteley to the PRI collections; it is
now PRI #49648.
PaleoPortal Undergoes Testing at MotE
The Devonian World hall at the
Museum of the Earth is the new
home to a computer kiosk associated with The Paleontology Portal.
PaleoPortal.org is a website serving
research and education communities that contains (1) paleontological, geological, and taxonomic data,
(2) a combined collections database
representing many museums (PRI’s
collections database became part of
this in April), and (3) various links
and images. Geological maps and
information about the paleontology
and geologic history of individual
U. S. states, Canadian provinces,
and Mexican regions form part of
the content. PRI is participating in
PaleoPortal’s development with a
grant from the National Science Foundation to create software to assist teachers, libraries or other organizations to easily assemble a custom-made dataset on the geologic history
and paleontology of their specific region. The resulting files
can be downloaded and used on any computer even without
an Internet connection. PRI’s test kiosk presents geology and
paleontology of the Northeastern U. S., and is a test site to
determine the usability of the kiosk by museum visitors.
Cayuga Nature Center/MotE Summer Camps
This June, July, and August, Cayuga Nature Center is partnering with Museum of the Earth to provide new and excit-
ing Summer Day Camp programs. Building on the strengths
of the CNC’s landscape, tree house, and animals, MotE is on
hand to add fossils, rocks, and so much more to the camp
offerings. Each of the nine weeks has a specific theme and
special guests to help provide awesome programming. MotEcentric themes include Wild Things Past and Present, Rock
This! and Dinosaurs of a Feather. Contact the CNC (http://
www.cayuganaturecenter.org) for more information.
Botany Through the Ages
A new school program, “Botany Through the Ages,” has hit
the ground rolling at Museum of the Earth. The moveable
cart includes fossils, fruits, seeds and living plants – cycads,
mosses, horsetails, and ferns – representing ancient lineages
to teach about the evolution of plants, from the Cambrian to
the present, and their importance to the evolution of animal
life on Earth. The plant cart can be seen in a sunny spot in
the Quaternary Hall at Museum of the Earth, or on the floor
during special programs. Our thanks go to volunteers Maureen Bickley and Lenore Durkee for helping to create the
program and the plant cart.
Dino Egg-Stravganza
If you missed the annual Dinosaur Egg Hunt at MotE to celebrate the Easter season, you missed a good one! The March
22 event broke all previous records, with more than 700 visitors in attendance. Collections of “dinosaur eggs” (actually
of the colorful plastic variety) hid throughout the Museum
created
excitement
and earned prizes for
kids of all ages. Key to
the event’s success was
two performances of
the Hangar Theater’s
“The Truth about
Dinosaurs,” a play of
three stories about
kids and their love of
dinosaurs – from a
paleontologist whose
son can only get her
attention by singing
rock songs about dinosaurs, to a boy who
thinks he’s turning into a dinosaur during his mother’s illness, to a tale about a dinosaur with feathers who is teased
even though she’s more evolved. Songs and costumes delighted visitors young and old. So, be sure to save the date
for next year!
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 5
F O C U S O N E D U C AT I O N
Climate Change 101
By Elizabeth Humbert
Part 3: Agriculture and Climate Change
Agriculture is one of the central pillars of
New York State’s economy – and as our
climate changes, our agricultural system
will change in response. One’s first thought
might be, “Well, warmer temperatures
mean a longer growing season and think of
all the great things we will be able to plant!”
This is true up to a point, but with warmer temperatures
come new problems, such as new pests and losses of crops
that can’t adapt to heat.
Don’t all of us here in New York occasionally wish for
a longer summer? It certainly felt like we got it this year …
the first hard frost in Ithaca was two to three weeks late.
So what’s the problem with this? Increased growing season
and increased carbon dioxide in the atmosphere (remember
that plants use CO2 for photosynthesis) could indeed boost
harvests. Unfortunately the flip side is that summers will not
only be longer, but also hotter, leading to greater evaporation
and therefore drier soil, even with the same amount of
precipitation. Drought could become a more frequent event.
Climate change can also bring extreme weather events. Some
of these, like heavy rainfall or thunderstorms, will bring
moisture, but also damage, in the form of floods and strong
winds. Crops will be under more stress, farmer costs will rise
as they try to mitigate these problems, and our precious water
resources will be increasingly taxed.
With milder winters and hotter summers, we will also see
an increase in pests that can infest and damage crops. Upstate
New York already has its share of damaging pests, but cold
winters often control population numbers and keep pests
from the more southern regions from moving north. For
example, the corn earworm, which is common in the south,
current lives only as far north as Ohio, Virginia, and southern
New Jersey. Cold winters keep it from permanently infesting
more northern regions. With milder winters, however, it
will easily be able to enlarge its range. An additional issue
with agricultural pests is that as summers become longer and
warmer, these organisms have additional time for breeding.
This means that more generations will be produced over the
growing season, and thus there will be more pests for longer
periods of time.
Some kinds of crops that are well adapted to New York
climate, and that have traditionally been a major part of
upstate New York’s economy, could move north. Can you
imagine New York without maple syrup or apples? Maple
trees, and the associated syrup industry, thrive in New
6 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
England and in upstate New York. Unfortunately, an earlier,
warmer spring could lessen the amount of maple syrup
extracted during sugaring season. Maple syrup is harvested
during a transitional time in early spring, when the weather
goes through freeze-thaw cycling, very cold nights with days
above freezing. This cycle stimulates the movement of sap
through the tree, and with an earlier and quicker spring,
we expect fewer days of sap movement and a diminished
harvest.
Apples too could be impacted negatively. Although a
longer growing season seems positive, many apple trees need
a certain number of days below freezing in order to set large
amounts of fruit. With warmer winters, many traditional
varieties of apples will no longer produce large amounts
of big fruit. Further, apples will bloom earlier. Spring
temperatures, as we well know, are incredibly variable, and
if bloom comes early, followed by frost, the flowers and fruit
could be damaged.
With climate change comes new weather patterns, new
water systems, and new ecosystems for plants and animals.
With each change, a new set of interactions must be
established between organisms and their environment. Rapid
and substantial changes are not sustainable.
In each of these columns, we pass on tips for you to
consider implementing in order to live “lightly” on the
world. Consider how our food and lifestyle choices maintain
or change New York ecosystems, and how they promote or
prevent sustainable agriculture.
TIP: Consider what food you buy and where it comes
from every time you are at the store. Try to buy items that
are sustainably grown ... perhaps they are locally produced,
and perhaps they are organic, or grown without pesticides or
antibiotics. You have to do what your household can afford.
But wouldn’t it be more sustainable to eat a locally grown
apple from upstate New York than an apple flown in, at great
expense, from New Zealand?
Part 4: Recreation and Climate Change
Ithaca is known for its beautiful scenery and outdoor
adventures! Residents and visitors have
access to great boating, golfing, and
fishing during the warmer months and to
the traditional outdoor winter sports like
skiing, snowboarding, and snowmobiling.
Unfortunately, as our climate changes,
many of these activities will be negatively
impacted. Traditional landscapes will change and problems
related to water shortages will increase. This could spell
trouble, particularly for industries built around tourism and
our traditional cold snowy winters.
According to the Union of Concerned Scientists, by the
end of the next century, New York State will see a temperature
rise of 6-7º F in winter, and 7-8º F in summer. We will also
see changes in weather and precipitation patterns. Although
the annual average will probably stay about the same, it is
possible that we will see more precipitation in winter, and
less in summer. Think about how that might change our
landscape: warmer summer temperatures mean greater
evaporation, with the prospect of more droughts and of
floods with rapid runoff. All of this could leave us with
warmer and drier summers, and winters would be less snowy
– with higher temperatures causing precipitation to fall as
rain instead.
How do these changes impact your summer activities?
Recreational boating will obviously be stressed by lower
water levels, but so will golf. Golf? Hotter, drier summers will
call for more water to be used to keep the local golf course
green. Rising demands for water in every sector, including
agriculture and the golf course, will stress water levels and
add new expenses to these industries. Golfers could see
these increased costs in reflected by higher fees and/or fewer
courses.
Recreational fishermen will also be affected by the
changing water system. Trout and salmon thrive in cold clear
water. As water warms, the fish populations will be hurt in all
stages of their life. The U. S. Forest Service predicts that over
half of the wild trout populations will likely disappear from
the southern Appalachian Mountains because of warming
water. We could see the same thing happen here in New York
State as regional ecosystems become increasingly inhospitable
to local fish populations.
Although we will definitely see changes to our summer
landscape, winter will really illustrate a dramatic change
in our climate. According to a Northeast Climate Impacts
Assessment (NECIA), snow is going to be an increasingly
scarce commodity in upstate New York. With rising
temperatures come warmer, rainier winters, and an absence
of snowpack. Some of us might look forward to a warmer,
less messy winter, but various economies and industries
dependent on winter snow will be devastated.
If the long snowy winters that are traditional in upstate
New York become a thing of the past, the alpine ski industry
will be in a particularly difficult position. A snowless year
can leave a resort deeply in debt, not only because of low
visitor numbers, but also because of extra time, money, and
energy spent on making snow. Not only will water resources
be stressed by snow production, but for the industry and
local economy this means fewer visitors, less profits, a shorter
season, and fewer employees, which can impact a struggling
resort town or region dramatically.
The U. S. Global Change Research Project states that over
the last 50 years, we have already seen a decrease of 7 days
in length of the snow-on-ground period in the Northeast.
As this decline continues, we will see more strain on the
Northeast winter tourism industry, which is second in the
country in numbers of winter recreation visitors.
Warmer winters and warmer summers will change
the landscape of upstate New York, and although we can’t
currently stop climate change, we can still be good stewards
of our natural areas and lakes and ponds. It becomes even
more important now to take care of our forests and wild
lands, as well as to protect the water supply from pollution
and overuse.
TIP: Recycle your Christmas tree. Every year 10 million
Christmas trees end up in landfills. Help keep your Christmas
tree out of the landfill by recycling it! Some towns have
curbside pick-up or if you live in Tompkins County you can
take your tree directly to the Tompkins County Recycling
and Solid Waste Center at 122 Commercial Avenue in Ithaca,
New York.
Elizabeth Humbert is former Education Resources Manager
and Global Change Coordinator at PRI and its Museum of the
Earth. Email [email protected].
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 7
B R I E F LY N OT E D
books of interest
Paleobiology
Evolutionary Statis and Change in the Dominican Republic Neogene edited by Ross H. Nehm and Ann F. Budd.
Papers on the Neogene paleoecology of the Dominican Republic as revealed by the Dominican Republic Project in the
1970s and earlier research. Springer (Topics in Geobiology
Series vol. 30), 314 pp., ISBN 978-1-40208-214-6, $219.00
(hardcover), expected June 2008.
Devonian Events and Correlations edited by R. T. Becker
and W. T. Kirchgasser. Papers on biostratigraphy, paleontology, and mass extinctions that characterize the Devonian Period, presented at an international symposium in March 2004
in Rabat, Morocco, honoring the late Michael R. House.
Geological Society Special Publication 278, 280 pp., ISBN
978-1-86239-222-9, $150.00 (hardcover), August 2007.
Grave Secrets of Dinosaurs: Soft Tissues and Hard Science
by Phillip Manning. The story of the “dinosaur mummy”
dubbed Dakota, from the preparations and excruciating care
taken during excavation, to the NASA CT scanner used to
examine the mummy’s interior, to the intact pollen found
in its stomach. National Geographic Society, 320 pp., ISBN
978-1-42620-219-3, $28.00 (hardcover), January 2008.
Dinomummy by Phillip Manning. A pictorial version of
the “Dakota” story, including stunning computer-generated artwork of the hadrosaur and its environment, written for young readers, ages 9-12. Kingfisher, 64 pp., ISBN
978-0-75346-047-4, $18.95 (hardcover), December 2007.
Polar Dinosaurs of Australia by Thomas H. Rich. Written for younger readers, a paleontologist describes the species and behavior of chicken-sized Australian dinosaurs at a
time when Antarctica could be reached by land; illustrated
by notable paleoartists. Museum Victoria, 48 pp., ISBN
978-0-97583-702-3, $9.95 (paperback), March 2008.
Mammoths: Giants of the Ice Age, revised edition by Adrian Lister and Paul Bahn. A visual record of one of Earth’s
most extraordinary species, including their dramatic Ice Age
habitats, photos of mammoth remains, and the art of prehistoric peoples who saw them. University of California Press,
192 pp., ISBN 978-0-52025-319-3, $29.95 (hardcover),
November 2007.
Neoproterozoic Geobiology and Paleobiology edited by
Shuhai Xiao and Alan J. Kaufman. Reviews of the Neoproterozoic Era (1000-542 Ma) fossil record, evolutionary de8 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
velopmental biology, molecular clock estimates of phylogenetic divergences, and chemostratigraphy and sedimentary
geology. Springer (Topics in Geobiology), 300 pp., ISBN
978-1-40205-201-9, $149.00 (hardcover), January 2008.
Bonebeds: Genesis, Analysis, and Paleobiological Significance edited by Raymond R. Rogers, David A. Eberth,
and Anthony R. Fiorillo. Papers on the study and analysis
of bonebeds – localized concentrations of fossilized vertebrate bones. University of Chicago Press, 400 pp., ISBN
978-0-22672-370-9, $75.00 (hardcover), February 2008.
Terra: Our 100-Million-Year-Old Ecosystem – and the
Threats That Now Put it at Risk by Michael Novacek. A
synthesis of evolutionary biology, paleontology, and environmental science applied to human impact in the current “mass
extinction.” The author is Provost at the American Museum
of Natural History and a 15-year explorer of Mongolian
Gobi Dessert fossils. Farrar, Staus and Giroux, 451 pp., ISBN
978-0-374-27325-5, $27.00 (hardcover), November 2007.
Big Bone Lick: the Cradle of American Paleontology by
Stanley Hedeen. The story of a woodland salt lick in northern Kentucky and how the fossil bones found there in the
18th century influenced the beginnings of paleontology
in America. University Press of Kentucky, 200 pp., ISBN
978-0-81312-485-8, $24.95, (hardcover), February 2008.
The New Taxonomy edited by Quentin D. Wheeler. Contributed papers discuss the future of descriptive taxonomy
in response to the challenges of the biodiversity crisis. CRC
Press, 256 pp., ISBN 978-0-84939-088-3, $99.95 (hardcover), April 2008.
The Earth on Show: Fossils and the Poetics of Popular
Science, 1802-1856 by Ralph O’Connor. Exploring how a
new geohistory more alluring than the six days of Creation
was assembled and sold to the Bible-reading public of Victorian Britain. University of Chicago Press, 448 pp., ISBN
978-0-22661-668-1, $45.00 (hardcover), January 2008.
Biology of Turtles edited by Jeanette Wyneken, Matthew H.
Godfrey, and Vincent Bels. A comprehensive review of Testudinata, including evolution of the shell and the relationships
of turtles within the amniotes. CRC Press, 408 pp., ISBN
978-0-84933-339-2, $149.95 (hardcover), December 2007.
Evolution and Darwin
Evolution by Nicholas H. Barton, Derek E. G. Briggs, Jona-
B R I E F LY N OT E D
books of interest
than A. Eisen, David B. Goldstein, and Nipam H. Patel. A
new textbook, more than half of which focuses on population
and evolutionary genetics (the expertise of the authors). See
supplementary material at http://www.evolution-textbook.
org. Cold Spring Harbor Laboratory Press, 833 pp., ISBN
978-0-87969-684-9, $100.00 (hardcover), June 2007.
More than Darwin: an Encyclopedia of the People and
Places of the Evolution-Creation Controversy by Randy
Moore and Mark D. Decker. Hundreds of entries of the people and places in this important controversy, including scientists, religious leaders, lawyers, and organizations. Greenwood Press, 448 pp., ISBN 978-0-31334-155-7, $85.00
(hardcover), March 2008.
Human Origins: What Bones and Genomes Tell Us About
Ourselves by Rob DeSalle and Ian Tattersall. What it means
to be “human” as revealed by DNA analysis, in this companion volume to the renovated Hall of Human Origins at the
American Museum of Natural History, New York City. Texas
A&M University Press, 216 pp., ISBN 978-1-58544-567-7,
$24.95 (hardcover), April 2008.
Big Brain: The Origins and Future of Human Intelligence
by Gary Lynch and Richard Granger. An exploration of human intelligence and creativity through comparison of modern humans and human-like “Boskops” who inhabited South
Africa 10,000 years ago with forebrains 50% larger than ours.
Palgrave Macmillan, 272 pp., ISBN 978-1-40397-978-0,
$26.95 (hardcover), March 2008.
Science, Evolution, and Creationism by National Academy
of Sciences and Institute of Medicine. Designed to provide
a comprehensive and up-to-date understanding of evolution
and its importance in the classroom for the general public.
National Academies Press, 70 pp., ISBN 978-0-30910-586-6,
$24.95 (paper or free pdf at http://www.nap.edu/sec), 2008.
Survival of the Sickest: a Medical Maverick Discovers
Why We Need Disease by Sharon Moalem and Jonathan
Prince. Written for a broad audience with a touch of humor,
a neurogeneticist examines debilitating hereditary diseases
and the consequences of aging from an evolutionary perspective. William Morrow, 288 pp., ISBN 978-0-06088-965-4,
$43.95 (hardcover), February 2007.
Earth Science
Field Guide to Plutons, Volcanoes, Faults, Reefs, Dinosaurs, and Possible Glaciation in Selected Areas of Arizo-
na, California, and Nevada, edited by Ernest M. Duebendorfer and Eugene I. Smith. Guidebook from the 2008 joint
meeting of the GSA Cordilleran and Rocky Mountain Sections contains background information and road logs for 11
field trips spanning the Ediacaran to the Holocene. Geological Society of America, 262 pp., ISBN 978-0-81370-011-3,
$50.00 (hardcover), 2008.
A Walk through Watkins Glen: Nature’s Sculpture in Stone
by Tony Ingraham. An “armchair guidebook” of the rocks,
water, plants, animals, and people along the trails of Watkins
Glen State Park through various seasons and times in Earth
and human history. Owl Gorge Productions, expected early
2008, see http://www.owlgorge.com.
Global Change
A Reef in Time: the Great Barrier Reef from Beginning
to End by J. E. N. Veron. The former chief scientist of the
Australian Institute of Marine Science highlights reefs as indicators of climate change. Belknap Press, 304 pp., ISBN
978-0-67402-679-7, $35.00 (hardcover), January 2008.
The World Without Us by Alan Weisman. The longevity of
our “environmentally poisonous footprint” is discussed within the hypothetical scenario of the Earth after mankind’s sudden disappearance. Thomas Dunne Books, 336 pp., ISBN
978-0-31234-729-1, $24.95 (hardcover, July 2007.
Six Degrees Could Change the World narrated by Alec
Baldwin. “What can we do about global warming – what
will happen to the Earth if we don’t?” A compelling view
of the world on the brink of major change precipitated by
climate change. National Geographic, DVD, 90 minutes,
ASIN B0012Q3T72, $19.98, April 2008.
The 11th Hour, narrated by Leonardo DiCaprio. Aimed
at the MTV-generation, this “mix of fear and inspiration”
informs viewers about the causes of global warming, and
how they can make a difference, from from eating organic to
building with solar power. Warner Home Video, DVD, 92
minutes, ASIN B00005JPXA, $4.99, April 2008.
Encyclopedia of Global Warming and Climate Change
edited by S. George Philander. Three volumes and more
than 750 articles that explore major topics related to global
warming and climate change, from North Pole to South Pole,
and from social effects to scientific causes. Sage Publications,
1552 pp., ISBN 978-1-41295-878-3, $299.20 (hardcover),
April 2008.
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 9
PALEONEWS
Virtual Paleontology Takes Another Step
Paleontologist Paul Tafforeau at the European Synchrotron
Radiation Facility in Grenoble, France, is able to see minute
fossils better than they’ve ever been seen. After centuries of
cutting and grinding by paleontologists, the technologies of
X-rays and CT scans have allowed fossils to be studied without damage, birthing the new field of paleoradiology. Now
another advancement has been made - synchrotrons. Synchrotrons use accelerated electrons of a single wavelength to
produce a kind of super-X-ray images called a propagation
phase contrast microradiographs. The images can be stacked
to reassemble the specimen just like CT scans. After using
synchrotronic images to study Neanderthal jaws, a 7-millionyear-old fossil ape skull, and yes, the embryos inside dinosaur
eggs, Tafforeau has now completed a landmark study of minute insects embedded in Cretaceous amber or fossilized tree
resin. We have all seen stunning pieces, or pictures of pieces,
of transparent golden amber containing lifelike entoumbed
insects (remember John Hammond’s walking stick topper in
Jurassic Park?), but in reality, 80% of amber is opaque, making study of its contents a particular challenge. Tafforeau’s
results with colleagues from University of Rennes, described
in an ESRF press release in April, yielded 356 specimens of
tiny (< 5 mm) fossils, including parts of plants, wasps, flies,
ants, spiders, and (dinosaur?) feathers (see following). Reassembled by a computer, the “virtual insect” (or other beastie)
can be rotated on-screen, or even more remarkably, “printed”
by a 3-D printer to produce a scale model in plastic. A further advantage is that these plastic models can be deposited
in a museum collection along with the original amber sample
and its otherwise invisible occupant.
First Look at Dinosaur Down
Among the small inclusions inspected by the French synchrotron (see above) are tiny feathers that could very well have
belonged to a feathered dinosaur. Features of the feathers are
quite primitive, similar to down feathers, lacking hooklets
known as barbules to hold the filaments together. Scientists
say that today’s birds could not fly with feathers such as these,
but current theories propose that dinosaurs first evolved
feathers not for flight but for insulation. The discovery has
been called a “most critical step in the evolution of feathers.”
These feathers are 50 million years younger than the first flying bird, Archaeopteryx, which lived 150 million years ago in
the Late Jurassic Period.
Biochemistry Confims Dinosaur-Bird Lineage
A nonavian dinosaur has finally participated in a molecular
phylogeny! Collagen proteins extracted from the demineral10 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
ized bones of a 68-million-year-old Tyrannosaurus rex place
it clearly with modern birds, supporting their position as the
descendants of dinosaurs. Authors Mary Schweitzer of North
Carolina State University (who wrote a feature article about
her techniques in the Spring 2007 issue of AP), John Asara
of Harvard Medical School, and other colleagues also used
mass spectrometry to measure the atomic properties of the
rare collagen (which once purified comprised less than a billionth of a gram), and found them most similar to those of
a chicken, confirming what is now a convincing accumulation of anatomical evidence for the dinosaur-bird link. The
success of this research has as much (perhaps more) to do
with the procedures used during collection of the bones, as
it does to laboratory techniques used in the analysis, leading
the authors to stress the application of field methods that
will not destroy whatever biochemical traces might still exist
in exceptionally well-preserved fossils. The team has applied
the same techniques to mastodon remains, and found them
(not surprisingly) most closely related to modern elephants.
Published in three research reports in April issues of the journal Science.
Tric on (and off) the Auction Block
A mounted, 70%-complete skeleton of the Late Cretaceous,
plant-eating, three-horned dinosaur Triceratops horridus went
on the auction block at Christie’s showroom in Paris in April.
This is arguably the most complete Triceratops skeleton ever
found. After failing to reach a minimal bid of 500,000 euros ($792,000) from bidders, including several museums, an
unnamed American collector came forward and bought the
skeleton for $944,167 (592,250 euros). The specimen is only
the second fossil of this caliber ever to be auctioned, following “Sue,” the Tyrannosaurus rex won at Sotherby’s in New
York by The Field Museum in Chicago in 1997; Sue’s price
was a whopping $8.3 million (partially financed by MacDonald’s and Disney). Individual Triceratops are estimated to have
reached 9 meters (29.5 feet) in length, 3 meters (10 feet) in
height, and 12 tons in weight. The shield-like skull is among
the largest of all land animals, sometimes reaching over 2
meters (7 feet) in length. It bore a single horn on the snout, a
pair of horns (one above each eye) and a flaring frill covering
the neck. The 7.5-meter-long skeleton at auction, originally
collected in North Dakota in 2004, was previously owned
by a German collector, who kept it sequestered in a museum
in his private chateau. Following the sale, an online cry was
heard for the scientifically significant fossil to be donated to a
museum where it could be enjoyed by the public and studied
by scientists. Reported by the Associated Press.
PALEONEWS
Earliest Bipedal Animal
The earliest known example of bipedal locomotion (walking
on two hind legs) has been claimed by a 6-million-year-old
fossil thigh bone from Kenya. Paleoanthropologists Brian
Richmond and William Jungers of George Washington University and SUNY Stony Brook said that the size of the hip
joint and the shape and strength of the wide thigh bone of
Orrorin tugensis both point toward bipedalism, a critical characteristic of what we call “humans.” Hand and arm bones
also indicate tree climbing, probably to eat, sleep, and take
refuge from predators. Characteristics of the skeleton also
surprisingly suggest a closer relationship to Homo (the genus
of modern humans) than to Australopithecus (the older lineage including the well-known “Lucy”), relegating the latter
lineage to a sidebranch of the human family tree. Only one
species of “protohuman” predates Orrorin – Sahelanthropus
tchadensis lived in what is now Chad nearly 7 million years
ago; however, its skull fragments are insufficient to establish
whether it walked bipedally. Reported in the 21 March issue
of the journal Science.
Flightless Birds Take Flight
Adelie penguins have reportedly rapidly evolved to reacquire
the ability to fly, in response to the shrinking Antarctic ice
shelf, which has severely reduced its breeding and feeding
grounds. Remarkable BBC-branded film footage on YouTube
shows the penguins –merrily hopping out of the water and
strutting across the ice per usual, after which they run, flap,
and take wing (presumably – but rather unbelievably – to a
tropical rain forest thousands of miles distant). In response,
ornithologists and birding enthusiasts worldwide have taken
up the cry against global climate change. Increased distributional range also puts the Adelies at risk from longline fisheries, which unintentionally drown large numbers of albatrosses and other sea birds each year. Longlining is the single
greatest threat to the world’s seabirds. Reported by Birdlife
International in January.
Is Paleontology Soft?
The sciences can and have been divided into two categories.
“Hard” sciences are the more technical, mathematical, quantitative disciplines such as physics and chemistry. “Soft” sciences such as psychology, biology, and yes, paleontology use
more subjective, observational or historical, qualitative data.
This categorization isn’t just philosophical. It translates into
research dollars, with the hard sciences often receiving the
lion’s share. A provocative article in The Varsity, an online Canadian student newspaper (http://www.thevarsity.ca), noted
in its April 7 issue that in the past 10 years, the Canadian
Institutes for Health Research awarded $3.4 billion to “hard”
biomedical research compared to only $465 million to a variety of “soft” sciences, including environmental and population studies. Based on trends felt by all paleontologists,
indeed all biologists, the same sorts of contrasting statistics
could probably be generated for U. S. funding agencies. Does
this mean that “soft” sciences are less deserving of research
dollars? Are the not “real science” too? Paleontology is put
forward in the article as providing “a unique insight into the
process of evolution without any use of mathematics.” (We
suspect some readers would argue this point.) The theory of
evolution, based largely on “soft” science, is cited as withstanding all scientific scrutiny to date. The article concludes
by noting that the distinction between “hard” and “soft” is
blurring (take molecular biology for example?), and that “the
search for knowledge” should forge mutual respect.
Crabs Broke Shells Even Earlier
PRI’s own Gregory Dietl (Director of Collections, and adjunct professor at Cornell University) discovered a remarkable Late Cretaceous crab, named Megaxantho zogue, in a
museum display case while visiting Mexico last year. The
oversized right “crusher” claw of the fossil with a large tooth
on the moveable finger is a dead ringer for one on modern
crabs that use their claw to peel, crush or chip the shells of
snails. Before this discovery, that feature in crabs was believed
to have evolved millions of years later in the Cenozoic Era.
The find opens a discussion of marine predator-prey relationships in the Mesozoic Era and how they might have helped
to shape the structure of marine communities. Reported online, with coauthor Francisco Vega (Universidad Nacional
Autónoma de México) in the March 10 issue of Biology Letters, published by the British Royal Society.
Devil Frog
A new species of fossil frog has been named from the Late
Cretaceous of Madagascar. This one is truly enormous – about
16 inches (40 cm) long and 10 pounds (4.5 kg) – about the
size of a housecat. It is likely the largest frog that ever lived. It
was given the charming name of Beelzebufo ampinga, meaning “armored frog from Hell.” More importantly, it has features that link it to a group of large-mouthed, predatory frogs
living today in South America, supporting the hypothesis of
a one-time land connection between that continent, Antarctica, and Madagascar, now off the eastern coast of Africa.
The strong jaws of the frog probably allowed it to capture
and feed on lizards and other small vertebrates, perhaps even
hatchling dinosaurs (!). Reported in the February 18 issue of
Proceedings of the National Academy of Sciences.
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 11
SUMMER SPECIAL
Fossils on the Beach
By Susan J. Hewitt
Do you visit the outer ocean beaches of New York and New
Jersey? And do you pick up seashells? Are you finding any
fossil shells? The answer is, “Yes, you almost certainly are,
whether you know it or not!”
On some of the exposed sand beaches of the outer Atlantic coasts of New York and New Jersey, the beach drift
can contain numerous fossil shells of bivalve and gastropod
mollusks. I can say that this certainly seems to be the case at
Long Beach, Long Island, New York, and the ocean beaches in Cape May County in southern New Jersey. The total
amount of beach drift present on a beach varies a lot from
day to day, and month to month. In the summer months
there is sometimes only a little shell material visible at low
tide, but drift is usually very plentiful after stormy weather.
On the beaches that I am familiar with, on days when there
is a lot of beach drift, there are usually lots of fossils present.
Sometimes fossil shells are nearly as common as fresh shells,
and always they are mixed in with the fresh shells higgledypiggledy in the drift lines.
It is not easy to tell which is which, and as a result, many
of us have brought home fossil shells without realizing it,
because to the casual eye they don’t look very different at
all from fresh shells. These fossils are not embedded in rock,
and they are still made of ordinary shell material. They are
no more fragile than the recent shells. They are not shells of
extinct, bizarre, or unfamiliar species. These shells are considered fossils only because they are so extremely old: they
are the remains of animals which lived during the Pleistocene
Epoch, more than 10,550 years ago.
Although these fossil shells are very old, they are shells
of species that still exist today on the eastern coast of North
America. These fossils look a lot like the other shells on the
beach, but most of the time, there are a few subtle differences
that can indicate which shell is one of these fossils, and which
is not.
First off, let me first say that yes, you will often find black
scallop shells on our beaches that are not fossils. They are
simply shells that have been buried for years in black anoxic
mud in the back bays. The sulphides in that mud have stained
the shells black.
The fossil shells have a few tell-tale signs. They do not
have any periostracum (the outer organic shell layer) or ligament (the elastic, organic structure that unites the two shells
of clams). Their original color has disappeared, so they show
none of the pretty coloring or patterning that some fresh
shells possess. In fact, the fossil shells tend to be oddly discolored: many are various dull and unnatural-looking shades
12 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
A fossil on the beach: one ancient valve of an Atlantic surf clam, Spisula
solidissima (Dilwyn, 1817), in the beach drift at Long Beach, Nassau
County, Long Island, New York, on 17 March 2008.
of gray, but they can also be off-white, tan, or faintly rustcolored. The most characteristic quality of these fossil shells
is that there is none of the high shine or partial translucence
that is typical of a fresh shell; instead the surface is opaque
and extremely dull-looking, even in the interior of the shell.
For a long time, collectors did not fully understand what
these odd-looking shells were. For example, in the classic
book on the living mollusks of this area, The Shells of the New
York City Area, by Jacobson and Emerson (1961), two marine species were described as found only as dead, discolored,
broken shells, or only as single valves. Noetia ponderosa (Say,
1822), the Ponderous Ark, is a warm-water species that cannot live this far north because the water here is too cold for
it to survive. In 1961, Jacobson and Emerson simply commented for this species and the periwinkle Littorina irrorata
(Say, 1822) that, “Some believe [they] have vanished because
of the increasing coldness of our off-shore waters.” In 1976,
in The American Museum of Natural History Guide to Shells,
the same two authors called local valves of Noetia ponderosa
“fossil-like” and wrote, “These northern populations were evidently exterminated by the cooling of the waters during the
Pleistocene.” In 1988, in another very useful book, Seashells
of Long Island by the Long Island Shell Club, some species
were listed as “subfossils,” a word meaning that the shells are
perhaps 5,000 years old, but not old enough to be a considered real fossils. A few other species are described as “dead
valves only,” and I think it’s quite likely that some of these
shells were true fossils.
It seems fairly clear now (at least on eastern Long Island,
as reported in 1976 by Thomas C. Gustavson of the University of Massachusetts) that these common “old” shells that
wash up on our beaches are not subfossils, but Pleistocene
fossils. These ancient shells are more than 11,550 years old,
and date from the last Ice Age or part of the Pleistocene Epoch. We tend to think of the Ice Age as a continuous time
of cold temperatures, with glaciers covering the land, but in
fact it was a time of extreme climatic fluctuations that were
cyclical in nature: there were very cold glacial periods, but
they were punctuated by warm interglacial periods, which at
their maximum were a lot warmer than the current climate!
As a climate changes, so do water temperatures, and when
the ocean water stays significantly warmer for a long period
of time, warm-water species have an opportunity to spread
up the coastline and start living in our area.
Perhaps it is worth explaining that, going from north to
south on the globe, scientists who study living faunas have
defined and named different “faunal zones,” each of which
has a group of characteristic species. Many species are not
found outside of their particular zone. Warm-water faunal
zones are home to many species that simply cannot survive
in colder water, and vice versa.
The Pleistocene fossil shells that you find on the ocean
beaches of New York and New Jersey are all species that still
live somewhere on the eastern coast of North America. In
fact almost all of the species still live in this general area, so
you will very likely find some of them as both fresh and fossil
shells. You might also notice that in any one locality, some
of the species are a lot more (or less) common as fossils than
they are as fresh shells.
If you search thoroughly enough, over a large number of
visits, you could eventually be lucky to find one or two fossil
shells of species which don’t live in New York and New Jersey anymore, species such as the Ponderous Ark mentioned
by Jacobson and Emerson. These are species that you would
expect to find in the warm waters of Virginia, the Carolinas
and northern Florida, in other words, the Carolinian faunal
zone. These southern species were able to live here during a
warm interglacial period, when the ocean water temperature
was 2-11ºC (3.6-19.8ºF) warmer than it is now.
Interestingly, if you keep searching, you could also find
fossil shells that have washed out of deposits from a slightly
earlier part of the Pleistocene, a glacial period when the ocean
temperature was 3-7ºC (5.4-12.6ºF) colder than it is now.
It is also worth mentioning that in addition to the ancient
shells, there are almost certainly shells on the beach that are
only decades or hundreds of years old: in other words, not
fossil or subfossil, just plain old.
Can we reliably tell how old a shell is that we find in
the beach drift? Not really. With experience, we can make a
guess, based on how the shell looks, but the only completely
reliable way to find out if a shell is ancient or not is to use
radiocarbon dating, which is expensive and inaccessible to
most of us.
So how is it possible to find fossils on the beach when
there are no cliffs for them to wash out of? Why do these
fossil shells and old shells end up on the outer beaches of
New York and New Jersey, along with the freshly-dead shells?
First we need to understand that the barrier islands on the
outer coast here are really nothing but very large, and rather
ancient, sand bars. Under the topsoil, these islands consist
of sand deposits of various ages: some old, some very old,
and some ancient. Despite modern efforts to stabilize these
islands as much as possible, it isn’t possible to stabilize them
completely, and so the edges of the islands are always being
reworked and reformed to some extent. In one area sand accumulates, while another part of the island is washing away.
Wherever the coast is being significantly eroded, either in
the intertidal zone or subtidally, then shells from the older,
much older, and ancient deposits are uncovered and exposed
to wave action. Often these old or fossil shells are carried
onto the beach, thanks to the churning action of the breaking waves.
So, when you are looking at beach drift on the outer
coasts this summer, be aware that among the fresh shells you
will very likely come across shells that are old, very old, or
ancient. You will almost certainly find fossils from the Pleistocene, specifically from the Ice Age. It’s good to remember
though, that you might not be able to easily discriminate
them from shells that are much more recent.
It’s not always easy being an informed beachcomber, but
it sure can be interesting!
Susan J. Hewitt is a Field Associate in the Division of Invertebrate Zoology, and a volunteer in the Division of Paleontology, at the American Museum of Natural History in New York
City. This article first appeared in a slightly different form in
New York Shell Club Notes, No. 376, September 2005 – June
2006, pp. 6-8. Republished with permission. E-mail: hewsub@
earthlink.net.
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 13
COMMENTARY
Mysterious Dinosaur Immunodeficiency Virus as a Possible Cause
of Sudden Dinosaur Extinction
By Mike Reda
Asteroid impacts or massive volcanic flows might have occurred around the time that dinosaurs became extinct, but a
new book argues that the mightiest creatures the world has
ever known might have been brought down by a tiny, much
less dramatic force – biting, disease-carrying insects.
Experts say that the evolution of insects could have been
an important contributor to the demise of the dinosaurs, especially the slow-but-overwhelming threat posed by new disease carriers. The evidence for this emerging threat has been
captured in almost lifelike-detail in the form of the many
types of insects preserved in amber that date to the time
when dinosaurs disappeared. “There are serious problems
with the sudden impact theories of dinosaur extinction, not
the least of which is that dinosaurs declined and disappeared
over a period of hundreds of thousands, or even millions of
years,” notes George Poinar Jr., a professor of zoology at Oregon State University. “That time frame is just not consistent
with the effects of an asteroid impact. But competition with
insects, emerging new diseases and the spread of flowering
plants over very long periods of time is perfectly compatible
with everything we know about dinosaur extinction.” This
concept is outlined in detail in What Bugged the Dinosaurs?
Insects, Disease and Death in the Cretaceous, a recently published book by George and Roberta Poinar (Princeton University Press, 2007). The authors suggest that insects have
played a major role in changing the nature of plant life on
Earth – the fundamental basis for all dinosaur life, whether
herbivore, omnivore, or carnivore. As the dinosaurs were declining, their traditional food items such as seed ferns, cycads, gingkoes, and other gymnosperms were largely being
displaced by flowering plants, which insects helped to spread
to dominate the landscape by their pollination activities. Insects could also have spread plant diseases that destroyed large
tracts of vegetation, and could have been major competitors
for the available plant food supply. “Insects have exerted a tremendous impact on the entire ecology of the Earth, certainly
shaping the evolution and causing the extinction of terrestrial
organisms ... The largest of the land animals, the dinosaurs,
would have been locked in a life-or-death struggle with them
for survival.” The authors claim that the confluence of new
insect-spread diseases, loss of traditional food sources, and
competition for plants by insect pests could all have provided
a lingering, debilitating condition that dinosaurs were ultimately unable to overcome. And these concerns – which
might have pressured the dinosaurs for thousands of years –
14 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
could have finished the job begun by changing environment,
meteor impacts, and massive lava flows.
According to paleontologist David Eberth, senior research scientist at the Royal Tyrrel Museum in Drumheller,
Alberta, Canada, the “Poinar concept” is not new. In the late
1980s, American palaeontologist Robbert Bakker suggested
that the influx of diseases and parasites had a profound impact on dinosaurs. The Poinar book presents the evidence for
this theory better than ever before in a highly organized manner which, according to Dr. Eberth, will help focus the next
generation of researchers in the right direction. Conversely,
François Therrien, also at Royal Tyrrel Museum, argues that
the Pointar book is a fantasy. Because insects were around for
many millions of years before the extinction of dinosaurs, the
Poinar concept fails to explain why the effect of insects only
occurred at the end of the Age of Dinosaurs and why it was
specific to dinosaurs.
The objective here is to support the Poinar concept by
speculating that an insect-carried dinosaur-specific immunofeficiency virus arose at the end of Age of Dinosaurs. Modern examples of this type of virus are (1) HIV (human immunodeficiency virus), specific to humans but not to dogs or
pigs, (2) Mad Cow Disease, specific to cows and deer but not
to snakes and birds, and (3) Bird flu, specific to birds but not
to dogs.Thus the sudden disappearance of dinosaurs can be
perhaps explained by an aggressive dinosaur-specific disease
that caused sudden death similar to that of camels in Saudi
Arabia. Evidence for such an occurrence would support the
Poinar concept and help to solve the Mystery.
Mike Reda is a consultant in Hamilton, Ontario, Canada. This
commentary was inspired by conversations with his 15-year-old
daughter, Marwalaine. Email [email protected].
FOSSIL FOCUS
Rudist Bivalves
By Ursula Smith
Left
Diceras moreaui Bayle
Late Cretaecous, Merry-sur-Yonne,
France
PRI 40174
Bob F. Perkins Collection
The specimen pictured here looks like part of a horn or even a horn coral, but it is actually one of the oddest looking bivalves
(clams) that you’re likely to see. It’s a rudist. The rudists form a taxonomic group of bivalves (Order Hippuritoida) that developed
many odd and distinctive morphologies. Like most other bivalves, they have two shells (although the specimen pictured here
shows only one of these), but they are strongly asymmetrical and are distinctive in reduction of their coiling. This reduction
produced progressively less coiled shells as the group evolved. Rather than looking like a classic clam, therefore, rudists display a
range of distinctive uncoiled shapes from “horn-like,” sometimes with two coiled shells, to “garbage can-like” (like Diceras, above)
in which one shell is a massive upright cone and the other forms a small coiled lid.
Rudists evolved during the Jurassic and Cretaceous periods but were, like the dinosaurs, ultimately victims of the endCretaceous extinction. They lived in warm, shallow seas at low latitudes, often forming or contributing to large carbonate
platforms and had a number of different life habits. Some were encrusters, and others simply lay around on the sediment. Their
most well known habit is the “elevator” type in which the shells grew upward and formed reef-like structures. These reefs were
not cemented together but rather consisted of loose sediment trapped between the shells, supporting them. Although rudist reefs
were less spectacular than the coral reefs we know today, rudists were major reef-builders in the Cretaceous and these structures
are often impressive in the field.
These odd bivalves aren’t just fascinating for paleontologists, paleoecologists, and carbonate petrologists, they also have an
important economic contribution. Their open internal structure, especially in the larger conical species, makes rudist reefs
excellent oil reservoirs.
FOSSIL
FOCUS
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 15
F E AT U R E A RT I C L E
Dinosaur Egg Detectives: Cracking the Case
By Charlie and Florence Magovern
Although dinosaur eggs were first identified in the 1920s, their
scientific significance was not fully appreciated until the end
of the 20th century. Today, dinosaur eggs are recognized for
their enormous scientific value – for offering fascinating details
and fresh insights into the behavior, growth, and evolution of
dinosaurs. The hunt for dinosaur eggs, nests, and young has
intensified in recent years as modern paleontologists pursue
these fossil treasures with new enthusiasm and purpose. How
do they know a dinosaur egg when they find it? And where
do they look?
The Earliest Discoveries
On July 13, 1923, near the Flaming Cliffs in Mongolia,
George Olson, a fossil preparator from New York’s American
Museum of Natural History, discovered what he believed to
be a dinosaur egg. At dinner that evening, he reported his
discovery to the other members of the expedition. They were
skeptical and passed it off, thinking that the objects could
only be sand concretions. The next day, Paleontologist Walter
Granger definitely identified them as eggs. Roy Chapman
Andrews, head of the expedition and presumed model for
3Indiana Jones of movie-fame, declared that they must be
dinosaur eggs. Andrews publicized and filmed the find and
was credited as the first explorer from the United States to
discover dinosaur eggs. He was overwhelmed by how much
public interest there was in the subject. [Chapman was,
however, not the world’s first discoverer or admirer of dinosaur
eggs – early humans drilled holes in dinosaur eggshells and
used them for adornment.]
The first written account about prehistoric eggs appeared
in France in 1859. A French priest and amateur geologist,
Father John Jacques Pouech, wrote that he had discovered
eggshells at the foothills of the Pyrenees in southern France.
But it was not until 1930 that a farmer plowing his fields
found the first complete French dinosaur eggs.
The first North American egg was found in northern
Montana in 1913. However, it was misidentified as a
freshwater clam until many years later when Dr. Jack Horner
found it in a drawer in the Smithsonian’s National Museum
of Natural History in Washington, DC, and identified it as
a dinosaur egg. In 1978, with the help of local rock shop
owners Marion and John Brandvold, Horner and his good
New York paleontologist Roy Chapman Andrews is credited with
discovery of the first dinosaur eggs in 1923. His showmanship
served as a model for the movie character Indiana Jones. Photograph courtesy of Library of Congress, Washington, DC.
Jack Horner re-identified a “freshwater clam” in the Smithsonian Institution collection as the first North American dinosaur
egg, collected in Montana in 1913. Photograph by Louie Psihoyos.
16 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
An oviraptor embryo is revealed within its delicate egg. The
skull, held by the calipers, is only one inch high. Photograph by
Louie Psihoyos.
Terry Manning’s acid-etching technique has extracted delicate
dinosaur embryo bones, as well as fossilized soft tissues and insects associated with the bones. Photograph by Louie Psihoyos.
friend Bob Makela discovered the famous “Egg Mountain”
nesting site in the Two Medicine Formation in northern
Montana, a treasure trove of dinosaur eggs and baby bones.
With this discovery, Horner paved the way for this new area
of paleontology.
Since that time, over two hundred dinosaur egg sites have
been found around the world. Individuals who are not degreed
paleontologists have made many of these discoveries. Father
John Jacques Pouech, George Olson, and the Brandvolds
paved the way for many more who followed. However, only
with the help of experienced paleontologists has the true
scientific importance of these discoveries been realized.
The Detectives
Dinosaur egg sites have been documented for many years but
not until recently have dinosaur embryos and hatchlings been
discovered. Fewer than two-dozen such finds have been made
in the entire world, the majority during the 1990s. Three of the
most amazing and inspiring discoveries of dinosaur embryos
were made in 1993 by three amateur paleontologists working
independently on material found in China and Mongolia.
These skillful, self-taught paleotechnicians worked to expose
the remains of dinosaur embryos so small and delicate that
the entire process had to be conducted under a microscope.
Terry Manning, of Leicestershire, England, revealed
embryonic dinosaur bones and tissues in 75-million-year-old
calcified eggs from central China. Using a revolutionary acidetching technique that he developed, the delicate remains of
fossil embryos are exposed by dissolving the surrounding
matrix in a weak solution of acetic acid. The specimens are
periodically washed and dried, and the exposed fossil material
is then impregnated with plastic to preserve it. His technique
is so fine in detail that he discovered fossilized soft tissue,
including muscle and cartilage, as well as evidence of the
insects that fed on the tiny embryonic carcasses.
Amy Davidson has worked for many years at the
American Museum of Natural History under the direction of
paleontologist Mark Norell. Her skillful steel-needle micropreparation techniques exposed an incredible Oviraptor
embryo collected by Dr. Norell during an expedition to
Mongolia in 1993. Oviraptor (“egg seizer” in Latin) was first
described by Henry Fairfield Osborn, director of AMNH
during the 1920s. The skull of one of these dinosaurs was
found during an expedition to Mongolia on the top of a nest
of what was long believed to be Protoceratops eggs. Osborn
speculated that the unfortunate Oviraptor had been caught
in the act of stealing eggs by an enraged ceratopsian parent.
The AMNH specimen prepared by Amy Davidson showed
the Oviraptor with its legs tucked beneath it, shielding the
nest. This observation proved that Oviraptor was not an “egg
seizer” as Osborne assumed but was, in fact, a caring parent
defending its nest!
Charlie Magovern discovered the only hatchling dinosaur
that has ever been found in articulated condition, that is,
with its bones aligned as they were in life. It also has the
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 17
Baby Louie’s skeleton (above) and a reconstruction of the chick
within its egg. Photographs by Louie Psihoyos.
Magovern has worked periodically on Baby Louie’s block with
a skillful and steady hand to remove the soft surrounding
matrix, grain by grain, with sharp needles made from thin
carbide rods. So far, he has found the embryonic bones of
two of Baby Louie’s siblings that were entombed inside other
eggs in the block. Apparently, Baby Louie emerged from its
egg into a hostile environment that preserved the clutch of
fully developed embryos at that moment in time.
From the very beginning, the experts agreed that Baby
Louie was some type of theropod, commonly referred to
as meat-eating dinosaurs. They determined this from the
structure of the eggshell and from Baby Louie’s hollow bones,
but it wasn’t clear what kind of theropod he was. It is not
always obvious which species of dinosaur laid a particular
egg, even when bones are found. This is because the skeletons
of embryos are (1) small and fragile, (2) initially made of
cartilage that does not preserve well during fossilization,
and (3) immature and sometimes without the characteristics
used to identify adults of the same species. Embryos are also
very susceptible to destruction by bacteria, insects, and other
predators prior to fossilization.
Initially, some thought that Baby Louie was Tarbosaurus
bataar, a Chinese cousin of Tyrannosaurus rex. Later, as more
bones were revealed, some thought that he was an obscure
dinosaur called a therizinosaur. In 1995, Canadian artist
Brian Cooley reconstructed the first life-like model of Baby
Louie based on the latter theory. The therizinosaur embryo
he created was featured on the cover of National Geographic
magazine. Magovern named Baby Louie after Louie Psihoyos,
distinction of being the only dinosaur hatchling ever
discovered at 2:00 am. “I was working late one night in
my preparation laboratory in Boulder, Colorado, on a large
block of eggs from central China that I had purchased from a
group of Chinese geologists,” Magovern recounted. “I knew
the block contained at least four giant dinosaur eggs, each
about 18 inches in length. I noticed what appeared to be
a few bone fragments in the chisel gouges left by the crude
Chinese excavation. I could not sleep until I confirmed
that this was something more than wishful thinking. After
two more hours of careful cleaning and inspection in this
miniature dig site, I had outlined what appeared to be a tibia
or perhaps a femur. I realized my limitations as an amateur
and sought the expert advise of paleontologists, Dr. Kenneth
Carpenter from the Denver Museum of Nature and Science
and Dr. Philip Currie from the Royal Tyrrell Museum,
Alberta, Canada to help identify what I had found and direct
me as to how to proceed.” Many more hours of painstaking
preparation revealed the largest and one of the most complete
dinosaur hatchlings ever found. Magovern nicknamed it
“Baby Louie.”
“Baby Louie”
Over the years, since the first exciting moment of discovery,
18 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
Reconstructed model of Baby Louie, by paleosculptor Gary Staab. Photograph by Florence Magovern.
who photographed it, as well as many other dinosaur eggs
owned by the Magoverns, for National Geographic’s story.
“The Great Dinosaur Egg Hunt” was published in the May
1996 issue of the magazine.
Who is Baby Louie – really?
Time inevitably brings new scientific discoveries to light,
unlocking some mysteries and creating new ones. In 1998,
more than five years after Baby Louie was discovered, new
clues to its identity began to emerge. Perhaps the most
irrefutable discovery was made in New York City in Mark
Norell’s office at AMNH. Magovern was there to deliver a
cast of Baby Louie that he was donating to the museum.
Norell went to a drawer and pulled out an identical match
to one of Baby Louie’s bones that had previously puzzled
scientists and defied identification. The bone was a lower
jaw of an oviraptor-type dinosaur from Mongolia. This new
information led to a new reconstruction of Baby Louie. The
new version was created by paleosculptor Gary Staab of
Golden, Colorado. He studied the actual Baby Louie skeleton
and compared it with the appearance and habits of modern
flightless birds such as emus and ostriches. His version of
Baby Louie is a feathered, oviraptor-type dinosaur chick.
Research by Darla Zelenitsky, at the University of
Calgary in Alberta, Canada, added more evidence that the
giant elongated eggs that Baby Louie hatched from were
laid by an immense oviraptor-type dinosaur much larger
than any previously known. She studied characteristics of
the eggs such as shape, size, ornamentation, and eggshell
structure, and compared them with similar, but smaller, eggs
found in Mongolia by Norell. The evidence concluded that
Baby Louie’s parents were members of the largest species
of oviraptorid yet known, although such an animal was
unknown at the time. As if in response, the 17-foot-tall
Gigantoraptor erlianensis was described from the Gobi Desert
in 2007 by researchers at the Chinese Institute of Vertebrate
Paleontology and Paleoanthropology.
Why feathers?”
Perhaps you ask, “Why feathers?” The evidence for feathers
comes from discoveries in the late 1990s of incredibly wellpreserved feathered dinosaurs including raptor-type dinosaurs
from Laioning Province in northeastern China. Further clues
indicating dinosaur feathers were found by comparing a tail
structure called a pygostyle that is found in both modern birds
and bird-like dinosaurs such as oviraptorids. The individual
tail vertebrae found in early birds such as Archaeopteryx were
later fused into a pygostyle, the final bone of the tail to which
cartilage and tail feathers attach.
Many different theories about the presence or absence of
feathers on dinosaurs are still argued, although the evidence
for feathers grows stronger with each new discovery. Some
scientists believe that young dinosaurs might have had downy
feathers for warmth rather than for flight.
A dinosaur egg, set against the Flaming Cliffs of Mongolia. Photographs by Louie Psihoyos.
Dinosaur detectives continue to study other clues that
could link dinosaurs and birds. Maniraptoran theropod
dinosaurs (raptor-type dinosaurs including oviraptorids) had
a furcula and fused clavicles. Both are used in modern birds
to support large flight muscles. A semilunate carpal (wrist
bone) was present in bird-like dinosaurs as in modern birds.
This is an extra bone in the wrist that allows the rotating
movement required for flapping the wing in flight.
The science of dinosaur eggs and embryos is still young,
and much is yet to be discovered by future generations
of Earth science enthusiasts. The mysteries surrounding
dinosaur eggs and who laid them will one day be solved by
the efforts of amateur and professional dinosaur detectives
working together to push the boundaries of knowledge of
the fascinating world of dinosaurs. Please visit the traveling
exhibit “Hatching the Past: Dinosaur Eggs” (at Museum of
the Earth and http://stonecompany.com/exhibits/index.html) to
learn more.
Charlie and Florence Magovern, of Boulder, Colorado, are
co-creators of the exhibit “Hatching the Past” now showing at
Museum of the Earth. Email [email protected].
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 19
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F E AT U R E A RT I C L E
Unscrambling Dinosaur Eggs
By Constance M. Soja
Some people prefer their eggs fried sunny-side up, poached,
in an omelete, or coddled, but I like mine fossilized – and
preferably laid by a dinosaur. For good reason, dinosaur eggs
are fascinating today to the general public and paleontologists
alike, but historically they were viewed as rare and enigmatic
curiosities without much scientific value. The first whole
dinosaur eggs were discovered in 1923 during an expedition
led by Roy Chapman Andrews to the Gobi Desert of
Mongolia (earlier finds of eggshell fragments in France and
Mongolia were thought to be from birds, but these are now
known to be dinosaur egg remnants). Until recently, the
eggs in Mongolia were believed to have been deposited by
Protoceratops, an early member of the ceratopsian (horned)
dinosaurs, because so many of that plant-eater’s bones were
found in close proximity to the egg clutch. In 1993, the first
fossilized embryo of a carnivorous dinosaur was discovered in
a Gobi egg identical to those collected in 1923. A 70-year old
case of mistaken identity was revealed when that specimen
– found cracked open like a diminutive Humpty Dumpty
frozen in time – showed the tiny, weathered remnants of a
baby Oviraptor, not Protoceratops! Even more remarkable was
the discovery of oviraptorid dinosaurs sprawled in broodinglike postures on top of similar egg clutches in Mongolia
and China. How extraordinary to see direct evidence that
a specialized form of parental behavior, common in many
bird species today, originated in birds’ evolutionary ancestors
– the dinosaurs. These and other important fossil finds have
fertilized a burgeoning interest in paleo-öology that continues
to intensify nearly 80 years after paleontologists were –
literally and figuratively – walking on eggshells of complete
dinosaur eggs for the first time.
Paleontological Significance of Dinosaur Eggs
In the past few decades, dinosaur eggs have been found at
more than 200 localities worldwide and on every continent
except Antarctica. Even though dinosaur eggs are not as
uncommon as was once supposed, those that pre-date the
Early Cretaceous (older than approximately 140 million
years) are rare. In fact, egg-laying strategies are known for
less than 2% of all dinosaur types (genera) so far identified.
Indeed, embryonic individuals preserved inside eggs as well
as fossilized “nests” and hatchlings are even less common
in the geologic record than the eggs themselves. Not
surprisingly, interpreting the fossil record of eggs has been bedeviled by the misidentification of nodules and concretions
(pseudofossils) as eggs, other cases of mistaken parentage
similar to that mentioned above, equivocal interpretations
Colgate’s Oviraptor egg. Notice the slight asymmetry in its oblong shape.
The rounded, blunt end (at top) is where an embryo’s head would have
been positioned, ready to “pop” out of the shell at hatching. The tail
would have wrapped around the hind legs, folded up in fetal position,
at the tapered end (bottom of photograph). The original eggshell is intact but broken along depressed fractures visible in this orientation of
the egg; the other side of the egg is mostly devoid of eggshell. See scale in
next photograph. Photograph from Colgate Viewbook, 2001, p. 16.
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 21
about how the adults might have arranged the eggs in a
“nest,” and debates about the ecological relationship (if any)
that existed between the eggs and the dinosaurs whose bones
are found nearby. Nevertheless, remarkable discoveries in
Mongolia, China, Patagonia, Montana, and elsewhere have
enabled paleontologists in recent years to produce detailed
descriptions of eggs, nest sites, and a working classification
of egg types. This useful “parataxonomy” is based on the
shape and size of the eggs and on the thickness, external
ornamentation (ridges, etc.), and microscopic features of the
eggshell, permitting similarities and differences among egg
deposits to be documented in a consistent way around the
world.
These important studies reveal new insights into dinosaur
reproductive strategies, which otherwise would be difficult to
extrapolate from the commonest of dinosaur fossils – their
bones and teeth. Because dinosaurs were highly successful
animals that dominated terrestrial ecosystems for more
than 150 million years, it should come as no surprise that
dinosaurs differed in how they constructed a “nest” for
their eggs, in their habitat preferences, how much parental
care they provided, tendencies for communal nesting, and
preference for a particular site for reproduction. For example,
the incompletely fused bones of young hatchlings preserved
in bowl-like depressions suggest, along with other evidence,
that Maiasaura dinosaurs were, as their name suggests,
“good parents.” Plant fossils found with the hatchlings imply
that the adults lined a well-prepared nest with vegetation
– perhaps for keeping the eggs warm or for the hatchlings’
food. The parents also seem to have guarded their helpless
young until the fledglings could leave the nest and fend for
themselves. Fossilization of “nests” in successive layers of rock
further suggests that Maiasaura dinosaurs returned year after
year to the same site for the annual rite of reproduction. In
contrast, lack of this kind of evidence suggests that many
other dinosaurs were able to reproduce successfully in ways
that did not require parental care or return to the same
nesting ground.
Specialists of dinosaur eggshells document how many eggs
occurred in a “nest” and their orientation with respect to each
other. They also try to determine what the eggshell’s chemical
composition can tell us about the environment and climate
where the dinosaurs were reproducing. Because the chemical
makeup of a modern chicken’s eggshell reflects the hen’s food
and water, dinosaur eggshells – particularly those that have
not been recrystallized or otherwise significantly changed –
can reveal if the parent dinosaurs lived in a dry or humid area
where certain plants or insects might have been eaten. Egg
shape, shell ornamentation and thickness, and pore densities
in modern eggs laid by crocodiles, alligators, and many birds
reveal details about nesting strategies, specifically whether the
eggs were laid openly – either in a natural depression on the
ground or raised above it – or were covered by a mound of
vegetation or buried in a hole in the sand. Similar details
22 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
recorded about dinosaur eggs and the rock in which they are
preserved can show if the dinosaurs created a particular kind
of nest along a river, sea coast, or desert.
Future research might even reveal clues into the causes
of dinosaur extinction. Cretaceous eggs deposited in the
last few million years of the dinosaur’s reign on Earth might
record evidence of a changing environment that contributed
to dinosaur extinction. Some scientists have even argued
that the eggs themselves were a primary factor in dinosaur
extinction. “How could this be possible? Perhaps changing
climate was not conducive to eggshell formation. Or is
there pathological evidence that dinosaurs began producing
abnormally thick eggshells that prevented their young from
hatching? Maybe Mesozoic mammals consumed all of the
dinosaurs’ eggs! However, like puffy but half-baked soufflés,
these airy ideas have deflated because of a lack of evidence to
support them.
Dinosaur Egg Taphonomy
Despite the extraordinary paleontological significance of
dinosaur eggs, their taphonomy – or the conditions that led
to their burial and fossilization – is poorly understood. In
fact, understanding the processes that increased or decreased
an egg’s chances of being preserved in the fossil record is a
fascinating but unsolved problem in dinosaur science. At
Colgate University, less than a two-hour drive from the
Paleontological Research Institution, special opportunities
exist to advance our knowledge about egg fossilization. That’s
because Colgate – through wholly improbable and fortuitous
circumstances – came to possess one of the first complete
dinosaur eggs known to science. Our 80 million-year-old
specimen is from the first clutch of dinosaur eggs found by
Roy Chapman Andrews and company in Mongolia in 1923.
The fossil egg arrived at Colgate after Andrews hatched a plan
in 1924 to stage a national auction to acquire funds for a
return trip to the Gobi. Fortunately for us, the winning bid
was made by Colonel Austen B. Colgate, who donated the
“Protoceratops” egg (now Oviraptor) to his university more
than 80 years ago.
Colgate Faculty-Student Research
At Colgate, we have undertaken burial experiments to
begin unscrambling the early stages in how an egg becomes
fossilized, using Colgate’s Oviraptor egg as a “case study” for
comparative analysis. These investigations add new data to
David Goldsmith’s earlier work that showed, using CAT scans
and X-rays, that our Oviraptor egg has no embryo preserved
inside its shell. Building on that research, David Sunderlin
and Steve Close buried over 100 alligator, chicken, emu, and
ostrich eggs in the laboratory and at two field sites in the
western U. S. We chose those particular egg types because each
approximates Oviraptor (or other dinosaur eggs) in shape,
size, and/or shell thickness. The external form of Colgate’s
fabulous egg (shown on the front cover of this issue) has the
FOSSIL STUFF
VOLUME 12
NUMBER 2
A NEWSLETTER FOR KIDS FROM
THE MUSEUM OF THE EARTH
SUMMER 2008
CREATED BY SAMANTHA SANDS, DIRECTOR OF PUBLIC PROGRAMS
DINOSAUR EGGS AND BABIES
Think of an egg. What does
it look like? How big is it?
Chances are that you are
thinking of a chicken egg like
the small white or brown ones
that you buy at the grocery
store. Many animals today
lay eggs – birds, crocodiles,
alligators, turtles, and most
snakes. And millions of years
ago dinosaurs laid eggs!
Dinosaur eggs were hard
shelled just like bird eggs and
have been found on every
continent except Australia
and Antarctica. Dinosaur
eggs were first discovered in
Mongolia in 1923 by a famous
paleontologist named Roy
Chapman Andrews and his
team of scientists. Today
over 200 dinosaur egg sites
have been found all over the
world and dinosaur embryos
have even been found inside
some of the eggs!
That’s EGG-cellent!
Oology is the study of eggs.
Eggs are made up of several
parts. The eggshell protects
the animal on the inside
and keeps the inside from
drying out. The eggshell has
thousands of pores all over
its surface to allow oxygen
in and carbon dioxide out
so that the growing embryo
can breathe. The white
part inside the egg is called
the albumen and its main
purpose is to protect the yolk
and provide nutrition for the
growing embryo. The yellow
inside of the egg is the yolk.
The yolk is the food source
for the growing embryo while
it is inside the egg.
All activities and images adapted with
permission from:
Hatching the Past Educators Guide
© StoneCompany.com, Inc., 2006.
Precocial or Altricial?
These words might seem big but their meaning is simple.
Precocial means that an animal takes care of itself right after it is born, with no help
from the parents. Snakes are precocial.
Altricial means that an animal needs care from its parents after birth. Rodents such
as mice are altricial. Based on the characterisics below decide whether you are
precocial or altricial.
Sauropod dinosaurs were precocial,
ready to run from the nest soon after
hatching.
Are you adventurous, self-sufficient,
and like to grab a bite to eat and
run? Then you are precocial.
Theropod dinosaurs such as
Oviraptor were altricial, needing
parental care when they hatched.
Do you like to know that someone
is near, prefer to work in a group,
and have someone make dinner for
you? Then you are altricial.
Scientists still debate whether ornithopod dinosaurs, like Maiasaura, were altricial or
precocial. Maiasaura nests in Montana are trampled with eggshell, baby bones, and
adults all in the same beds. In China, ornithopod nesting sites are filled with nearly
complete hatched eggs that imply that the hatchlings left the nest quickly. What do
you think? Are ornithopods precocial or altricial?
Did Baby Dinosaurs Look Like Their Parents?
Most dinosaurs looked very much like their parents when they were born, but some
features, such as horns and frills, took time to develop.
Adult Protoceratops
Number the pictures below in order, to show how a baby Protoceratops grew.
EGG-speriments:
Why Don’t Mothers Break Their Eggs?
This experiment is to demonstrate the strength of eggshells. It demonstrates that
mothers can sit on nests of eggs without breaking them.
You will need the following materials:
•
•
•
•
Six large raw eggs
3-4 heavy books (such as dictionaries)
Plastic food wrap
A soft depression in the grass outside or a sandbox (if you can not travel outside, fill a large
plastic storage bin with a few inches of sand or dirt, making sure that there is enough room
to stack the books over the depression without the books resting on the storage container)
Procedure:
1. Do you think eggs are strong? Crack an egg. Doesn’t seem very strong does it?
2. Gather the materials and head outside. Find or make a small depression in the
ground so that the eggs won’t roll away but still stay above ground.
3. Cover the eggs with a piece of plastic food wrap (just in case the eggs break, so
the books won’t get damaged).
4. Slowly and gently set one book on top of the eggs. Observe the eggs to make sure
that they are still whole. Continue putting on books (until you have about 3 or 4).
5. Do you know why the eggs did not break? Eggs have an arc-like structure that
supports the weight in several places, not at just one single point. The weight
travels along the curve of the egg to displace the weight to the widest part of the
dome.
Even more fun science:
To quantify the amount of weight that these six eggs can hold, continue placing books on
the eggs until one breaks. Then weigh the books placed on top to see how much weight
the eggs held. To be a good scientist, repeat this experiment several times and compare
results to get an average for the amount of weight six eggs in a nest can hold. See if you
can estimate the amount of weight dinosaur eggs could hold by comparing the size ratio of
a chicken egg to a dinosaur egg and then making a weight ratio for the amount of weight
that the chicken eggs held versus the amount of weight that dinosaur eggs might hold. Is
the weight approximately the same as the dinosaur that might have laid the eggs? Is this
perhaps why some dinosaurs were good mothers and tended their nests and young, and
why other dinosaurs laid the eggs and left the babies to defend themselves?
Eggs used in our taphonomy research. (Above) Relative sizes and shapes
of eggs in study (clockwise from upper left): ostrich, emu, chicken, and
alligator, around Colgate’s Oviraptor egg at center; (right) alligator egg
showing collapse feature; and (right, below) fractured ostrich egg filled
with sand. Scales = 3 cm (approximately 1.25 inches).
look and shape of an overdone baked potato: it is oblong
but slightly asymmetrical in shape (the blunt, rounded end
would have accommodated the growing embryo’s head) and
has about 60% of its original eggshell intact (the depressed
shell fractures probably formed after burial). Those four
egg types were also valuable in our research because they
represent reptile or bird species that belong to evolutionary
lineages closely related to the dinosaurs. They are also readily
available fresh year-round, either commercially or at wildlife
parks and exotic species farms, and they are not prohibitively
expensive.
The eggs were dug up at prescribed intervals over a threemonth period. Not so surprisingly, our pilot study showed that,
as anyone knows from the kitchen and – more recently – the
fossil record, eggs are both fragile and resilient. Beyond that,
we have interesting new insights into: (a) the chronological
stages in the fracturing, decay, and disintegration of eggs
exposed at the surface and buried in sand, (b) the effect of
other organisms (scavengers, burrowers, plant roots, etc.)
and of nonbiological agents (wind-driven movement of
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 23
sand, eggshell dissolution by acidic groundwater, etc.) on the
rates and patterns of egg transport, removal, or loss, and (c)
directions for future research.
Egg fragility was most obvious in the extensive fractures
that stretched like a spider web across the surface of many
of the eggs we buried. Portions of some eggs collapsed after
the yolk and whites had seeped out, allowing shell fragments
to filter inside the egg. In one specimen, a gaping hole was
produced by a scavenger’s bite, probably a coyote’s. However,
the eggs that were buried for three months also showed
tremendous strength and resistance to breakage and decay.
None of the buried eggs was crushed flat or reduced to a
splayed mosaic of squashed shell fragments. This resilience
can be explained by the egg’s shape, which is naturally
much stronger than appreciated. [To show how true this is,
place a whole, raw, jumbo-sized chicken egg, which weighs
approximately 2 ounces (56 grams) and has an eggshell less
than 1/16 inch (< 1 millimeter) thick, in a plastic, zippable
bag, making sure that the bag is completely zipped. Attempt
to crush the egg by squeezing it at both poles simultaneously,
applying as much force as you can equally with both hands.
If no luck, rotate the egg and squeeze it with both hands on
either side of midline – note how much easier it is to crush
the egg in that orientation!]
Why is an egg so easy to crack against the edge of a
mixing bowl and yet so resistant to crushing with both
hands? To answer that question, it helps to think of an egg
as two domes joined together. The egg’s two slightly pointed
ends (its poles) form the architect’s dream element, an “arch,”
which can withstand considerable force because pressure is
evenly distributed across its curved, dome-like surface. The
eggshell is flatter (has less curvature) where the two domes
meet, explaining why the egg is weaker along its midline, just
where we tend to crack an egg against the rim of a bowl and
where a bird hatchling uses its egg-tooth to chip its way out
of the shell.
Our research shows, however, that shape alone does not
explain how an egg survives the ages to enter the fossil record.
Significantly, the stretchy, latex-like membrane that lines the
inside of the shell (still evident in some of our eggs after three
months of burial) acts as an important adhesive. It helps to
“glue” shell pieces together that are starting to fracture during
the initial phases of burial. Sand (or other sediment) also
plays a role in providing structural support to the egg. Our
study showed that sand sifted into the shell along fractures
and through gaping holes, becoming an early replacement of
the egg’s soft contents after they had leaked out. By filling the
egg’s interior, the sand prevented its further collapse.
Even though our study showed that many processes
contribute to egg preservation, it also revealed how biologic,
physical, and other agents can destroy eggs. Over our threemonth study period, the wind removed a meter (3 feet) of
sand from above a buried clutch, leaving the eggs exposed at
the surface where they were more susceptible to weathering,
24 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
transport, and scavenging. In fact, scavengers removed
approximately 70% of the eggs at one field site. Fossil
eggs are rare in the fossil record so it is clear that multiple,
competing processes dictate which ones survive to the present
day. Because our pilot project was limited to three months,
we could not observe long-term processes at work. Thus the
chance to explore the Mongolian site where the Colgate egg
was collected presented a special opportunity to uncover
clues about how ancient environmental conditions there
might have favored egg preservation.
Insights from the Gobi
Colgate’s dinosaur egg was collected at an unrecorded
location at Bayan Zag in the Gobi Desert close to where
additional egg clutches were unearthed by Andrews and
others in 1925. Photographs and field notes taken during
the 1925 expedition indicate exactly where those eggs were
found – high on the top of an escarpment in an area called
the Flaming Cliffs. Wind-deposited sandstones at the base of
the cliffs indicate that 80 million years ago this part of the
Gobi was covered by active (unvegetated) and stabilized sand
dunes with seasonal ponds and streams. The 1925 egg clutches
were found in the strata that form most of the cliffs above the
sandstone deposits. Perhaps what is most remarkable about
these very fine-grained, pink-red, crumbly sandstones is not
what they contain but what they lack. Except for traces left
by burrowing animals and concretions (or “pseudofossils,”
pea- to boulder-sized nodules caused by cementation around
a nucleus), the sandstones are massive and almost entirely
featureless. Notably absent are fine and coarse layers of sand
grains, rippling, scouring, and cross-bedding – all features
that typically form when sediment is transported across a
dune by wind or carried by water along a riverbed. High in
the upper part of the massive sandstone sequence, several
distinctive beds less than a foot (< 0.3 m) thick are especially
noteworthy. Densely packed with gravel- to fist-sized white
concretions, they are harder than the surrounding sand layers
and, as such, are weathered out in relief and easily traceable
across the landscape.
A working hypothesis about the origin of the massive
sandstones (published by others and modified here) is that
the very fine-grained sand settled into place after fierce desert
sandstorms. The nodular beds packed with concretions that
punctuate this sequence represent caliche (calcrete) horizons.
These probably formed when elements in the soil – principally
calcium carbonate – were mobilized during intense rainfall
events and precipitated hard layers afterwards.
That two clutches of dinosaur eggs were collected in
1925 high in the stratigraphic section between caliche layers
is important. When considered together with other evidence,
this suggests that a population of Oviraptor dinosaurs –
breeding successfully in a sandy dune-scape – suffered, as
sometimes happens in Nature, from occasional catastrophic
events. Desert sandstorms that might have raged for hours or
days appear to have carried enough sediment aloft to bury the
eggs (and sometimes also suffocate the brooding adults). After
burial, the eggs cracked under the weight of the overlying sand
and then filled with sand. The fragmented shells stayed intact
because of the membrane’s adhesive properties and also the
internal support provided by the sand-casting process. Intense
rainstorms induced rapid cementation during formation of
the caliche, protecting the eggs under a hard, durable crust.
This extraordinary set of events explains at least in part how
the eggs escaped being compressed, crushed, or flattened over
the course of 80 million years.
Summary
As readers of American Paleontologist know well, paleontology
requires hard-boiled detective work to successfully delve
into the intriguing world of fossils. The work of fellow
scientists – in this case, Jack Horner, Ken Carpenter, Mark
Norell, Michael Novacek, David Fastovsky, Jim Hayward,
Lowell Dingus, Chuluun Minjin, and many others – lays
an important foundation for pursuing new lines of study.
Our work at Colgate shows that the earliest stages in the
fossilization of whole eggs can be explained in part by our
taphonomic experiments. Our results emphasize how the
architectural anatomy of the egg, its internal membranes, and
the infilling sand can elevate an egg’s potential for becoming
preserved. Yet our study also shows that within a very short
period of time, eggs begin to fracture and experience weight
change, sand casting, decay, and loss through scavenging.
Critical conditions, such as rapid burial and cementation,
appear to have been very important in the preservation of the
famous Oviraptor egg clutches at Bayan Zag. In addition to
these preliminary conclusions, our pilot project sets the stage
for the design of long-term experiments that should help
determine the chronological stages that eggs pass through on
their way to becoming fossils. Even though our hypotheses
at this stage are a bit like oeufs en gelée – just beginning to
firm up and take shape – perhaps they will inspire interest
in eggs past and present, including those on exhibit at PRI’s
Museum of the Earth.
Further Reading
Andrews, R. C. 1932. The New Conquest of Central Asia:
a Narrative of the Explorations of the Central Asiatic
Expeditions in Mongolia and China, 1921-1930. American
Museum of Natural History, New York.
Bausum, A. 2000. Dragon Bones and Dinosaur Eggs: a
Photobiography of Explorer Roy Chapman Andrews.
National Geographic Society, Washington, DC.
Carpenter, K. 1999. Eggs, Nests, and Baby Dinosaurs: a Look
at Dinosaur Reproduction. Indiana University Press,
Bloomington, Indiana.
Carpenter, K., K. F. Hirsch, & J. R. Horner, eds. 1994.
Dinosaur Eggs and Babies. Cambridge University Press,
New York.
Chiappe, L. M., & L. Dingus. 2001. Walking on Eggs: the
Astonishing Discovery of Thousands of Dinosaur Eggs in the
Badlands of Patagonia. Scribner, New York.
DeVito, A. 1982. Teaching with Eggs. Creative Ventures,
Lafayette, Indiana.
Horner, J. R., & D. B. Weishampel. 1989. Dinosaur eggs: the
inside story. Natural History, December 1989: 60-67.
Mikhailov, K. E. 1997. Eggs, eggshells, and nests. Pp
205-209, in: Encyclopedia of Dinosaurs, P. J. Currie &
K. Padian (eds), Academic Press, New York.
Norell, M., J. M. Clark, L. M. Chiappe, & D. Dashzeveg.
1995. A nesting dinosaur. Nature, 378: 774-776.
Norell, M., et al. 1994. A theropod dinosaur embryo and
the affinities of the Flaming Cliffs dinosaur eggs. Science,
266: 779-782.
Novacek, M. 1994. A pocketful of fossils. Natural History,
103: 40-43.
Novacek, M. 1996. Dinosaurs of the Flaming Cliffs.
Doubleday, New York.
Novacek, M. J., M. Norell, M. C. McKenna, & J. Clark.
1994. Fossils of the Flaming Cliffs. Scientific American,
271: 60-69.
Searl, D., & J. Horner. 2006. The Maiasaura Nests: Jack
Horner’s Dinosaur Eggs (Fossil Hunters). Bearport
Publishing Company, New York.
Soja, C. M. 1999. Using an experiment in burial taphonomy
to delve into the fossil record. Journal of Geoscience
Education, 47: 31-38.
Soja, C. M., D. Sunderlin, S. J. Close, & B. White. 2005.
“Éclosion fenetre” and dinosaur egg taphonomy. North
American Paleontology Convention, Programme and
Abstracts. PaleoBios, 25 (suppl. to no. 2): 110.
Sunderlin, D. F., S. J. Close, & C. M. Soja. 1999. Digging for
answers: a taphonomic analysis of a Mongolian Oviraptor
philoceratops egg. Geological Society of America, Abstracts
with Programs, 31(2): 71.
Thulborn, T. 1992. Nest of the dinosaur Protoceratops.
Lethaia, 25: 145-149.
Varricchio, D. J., F. Jackson, J. J. Borkowski, & J. R. Horner.
1997. Nest and egg clutches of the dinosaur Troodon
formosus and the evolution of avian reproductive traits.
Nature, 385: 247-250.
Connie Soja is Chair and Professor of Geology at Colgate University and a former President of PRI’s Board of Trustees. She
thanks Colgate University, Brian White, David Goldsmith,
David Sunderlin, Stephen Close, Christopher Maslanka, Julia
Shackford, Jon Bedard, Michael Bernstein, and Russell Colgate
Wilkinson for support of dinosaur egg research. Email csoja@
mail.colgate.edu.
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 25
DODSON ON DINOSAURS
Paleontology Done Right - Mejungasaurus crenatissimus
By Peter Dodson
Paleontology has been a richly satisfying career choice for
me. Myriad aspects have given me pleasure. The objects
themselves – whether Cambrian trilobites, Ordovician
corals, Carboniferous ferns, Cretaceous ammonites, Eocene
fishes, or Pleistocene elephants – are intrinsically beautiful.
The study travel to interesting places off the well-trodden
paths of tourists, the dirt under the fingernails, life around
the campfire under the bright stars, the consumption of
sometimes excessive quantities of ethanol at meetings – it is
all good. For more than a decade, it has been my pleasure to
write on diverse topics to the readership of this periodical.
All scientists are writers, although not all enjoy writing to
the same degree. In these days of soundbites and headline
news, monography like monogamy is an underappreciated
art. Monographs were once a staple of paleontology. On
my bookshelf sit treasured original copies of such classics as
Marsh’s 1896 Dinosaurs of North America, Lull & Wright’s
1942 Hadrosaurs of North America, and above all Hatcher,
Marsh, & Lull’s exquisite 1907 The Ceratopsia. I have the
1940 Brown & Schlaikjer Protoceratops monograph in two
media, a photocopy of a photocopy via Dale Russell, and a
PDF from Jerry Harris, both very much valued, but I really
covet an original hard copy (to use a redundant phrase!).
In 1991, the Society of Vertebrate Paleontology initiated
a distinguished series of memoirs. Since that time, eight
memoirs have appeared, two each by Lance Grande and Willy
Bemis in 1991 and 1998 on osteichthyan fishes, Paul Sereno
on basal archosaurs (1991) and sauropods in 1998 (the latter
with Jeff Wilson), and Chris Brochu Tyrannosaurus (2002)
and on alligatoroid morphology and phylogeny in 1999 (with
Tim Rowe and K. Kishi). Larry Witmer had a solo in 1997,
a veritable classic on the antorbital cavity of archosaurs, from
basal forms to birds. I wrote on Brochu’s monograph five
years ago in this space [see “Tyrannosaurus Lex,” AP 11(1):
6-9, February 2003]. After a six-year hiatus, the object of my
present affection is SVP Memoir 8, a wondrous monograph
edited by my good friends and colleagues, Scott Sampson
(University of Utah) and David Krause (Stony Brook
University) with the title of “Majungasaurus crenatissimus
(Theropoda: Abelisauridae) from the Late Cretaceous of
Madagascar” (Sampson & Krause, 2007). The theropod
from Madagascar is lovingly documented in 184 dense pages.
Seldom has a single species of dinosaur received such dense
and admirable coverage!
Greater than the monograph itself is the entire Mahajanga
Basin Project (MBP), a joint project of Stony Brook University
and the University of Antananarivo. In keeping with the joint
26 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
nature of the project, abstracts of each paper are also presented
in the Malagasy language. Everything about the project has
been done right. In 1993, David Krause went to northwestern
Madagascar in search of rare Cretaceous mammals. Although
he succeeded in that goal, he was vastly more successful in the
realm of Cretaceous archosaurs (crocodiles, dinosaurs, and
birds). Not only has the project generated stellar scientific
results, it has served as a great training ground at Stony Brook
for students and young colleagues. Patrick O’Connor, now at
Ohio University, used the vertebral column of Majungasaurus
as a springboard for a wide-ranging PhD dissertation on
pneumaticity in archosaurs, including birds (O’Connor,
2003). Kristina Curry Rogers (Macalester College, Science
Museum of Minnesota) had the privilege of describing
the skull and skeleton of a new titanosaurian sauropod,
Rapetosaurus krausei (Curry Rogers & Forster, 2001),
which formed the nucleus of her PhD dissertation on the
evolutionary history of the titanosaurs (Curry Rogers, 2001).
Madagascar did not launch the careers of my student, Cathy
Forster (PhD University of Pennsylvania, 1990), who had
already established her career with her work on Tenontosaurus,
Chasmosaurus, and Triceratops, but it allowed the young
anatomy professor to supervise students at Stony Brook for
the first time (O’Connor, Curry Rogers) and also to take the
The jaw of an abelisaurid theropod excavated in Madagascar in 1996.
A Swiss Army knife is included for scale. Photo courtesy of Dave Krause
and Larry Witmer.
lead in describing some very important primitive bird fossils,
Vorona and Rahonavis (Forster et al., 1996, 1998). This also
was the case for Scott Sampson, then a young anatomist at
New York College of Osteopathic Medicine of New York
Institute of Technology at Old Westbury, New York, just
down the road from Stony Brook. Scott had already begun
his career with a splash, describing two new genera of horned
dinosaurs from Montana, but Madagascar gave his career
a huge boost. Like Cathy and Patrick, Scott jumped into
fieldwork in Madagascar with boundless energy. He played
a key role in the discovery of the Majungasaurus skull in
1996, and he took the lead in the description of the domed
skull (Sampson et al., 1998). Three years later, Scott again
took the lead in describing the small theropod Masiakasaurus
(Sampson et al., 2001). Scott then went on to an excellent
career at the University of Utah.
Yet another dimension of the Mahajanga Basin Project
is humanitarian. I have written before of David Krause and
the Madagascar Ankizy Project [see “Paleontology with a
Conscience,” AP 12(1): 5-6 and 16, February 2004]. David’s
efforts have led to the construction of several schools in the
The author with the left jaw of an abelisaurid theropod in the field in
Madagascar in 1996.
rural countryside of northwestern Madagascar. With the help
of countless contributions from school children, colleagues,
and the public at large (and this means me and you!), he has
also purchased school supplies, paid the salaries of teachers
($250 per annum), and has brought medical and dental
services from Stony Brook University for the villagers each
summer that he has returned there.
Compared to the humanitarian efforts, the monograph
is only a monograph, but it really is a very good one. It
answers some fundamental questions that paleontologists are
frequently asked. For example, “How do you know where
to find fossils?” One very legitimate answer: “Where others
have found fossils before.” The first dinosaur fossils from
northwestern Madagascar were described by the French
paleontologist Charles Depéret in 1896. Depéret did not
collect the fossils, but received a shipment in Lyons from
a French military doctor, who recognized the fossils from a
unit that is now called the Maevarano Formation of latest
Cretaceous (Maastrichtian) age. He recognized several
dinosaurs among the fragments, and described two new
dinosaurs, “Megalosaurus” crenatissimus and “Titanosaurus”
madagascariensis (the quotation marks around the names
of both genera reflect the poor quality of the specimens
upon which the names are based, which has made it almost
impossible to refer new specimens to the genera). The best
of the specimens was a partial jaw with empty tooth sockets.
A very important partial skull evidently made its way to
Paris around the beginning of the twentieth century. The
Frenchman René Lavocat was probably the first professional
paleontologist to collect in the region of the village of
Berivotra, which is the most productive fossil locality in
the region. In 1955, Lavocat recognized the inadequacy
of the name “Megalosaurus” and so coined the new name
Majungasaurus crenatissimus (meaning “very highly notchtoothed reptile from Majunga”), using the colonial name for
the port city that has since reverted to its Malagasy name,
Mahajanga. Despite its new name, the theropod remained
poorly known. Further French expeditions in 1976 and 1989
continued to yield fragments. An important milestone was
the publication of the partial skull at the Museum of Natural
History in Paris by Sues and Taquet (1979), who felicitously
named Majungatholus atopus, the “out of place dome from
Majunga,” as a putative pachycephalosaurid dinosaur. Out
of place indeed! This group of enigmatic ornithischian
plant-eaters is otherwise known strictly form the northern
hemisphere.
This sets the scene for the wildly successful MBP
expeditions led by Krause (1995, 1996, 1998, 1999, 2001,
2003, and 2005) that resulted in the discovery of an entirely
new dinosaur fauna and fossil ecosystem consisting of more
than 40 species of vertebrates from fishes to mammals.
The harvest of theropod teeth alone accounts for literally
thousands of isolated specimens. Why did the French fail
over nearly a century to find skeletons? One possible answer
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 27
is an aversion to manual labor! I will explain. David Krause
had a genius in assembling a team of eager and skilled
excavators. It was my privilege in 1996 to be a member of
Krause’s team. Florent Ravoavy, our Malagasy colleague who
was also a member of the 1989 French expedition, brought
us to a spot where the French workers had collected four
theropod tail vertebrae seven years previously. A bench on
the hillside was literally strewn with bone, and fairly cried
out in flashing neon lights “Dig here!” Yet our colleagues
from the Seine evidently did not see fit to exert themselves
unduly in the tropical sunshine, but contented themselves
with picking up the same sort of fragments that had been
collected for the previous century. Here we dug, and here we
encountered one of the most memorable specimens of any
paleontological career: the complete disarticulated skull of an
abelisaurid theropod, complete with menacing teeth. My own
contribution to the skull was the left dentary. Best of all, there
was dome on top of the skull. We published a description of
the skull in Science (Sampson et al., 1998), announcing to
the world that Majungatholus was no pachycephalosaur at all,
but rather an abelisaurid theropod. I wrote of my wonderful
experiences in Madagascar in one of my very first essays for
this magazine [see “Dinosaurs in the Developing World,” AP
4(4): 3-5, November 1996].
Since then, my career has developed in different directions
but I have followed the results of MBP with great interest.
I was surprised to remark that further study has led to the
reasonable conclusion that there is only one large theropod in
Maevarano ecosystem, and that the appropriate name is the
somewhat more pedestrian Majungasaurus Lavocat, 1955,
rather than the more memorable name Majungatholus Sues
& Taquet, 1979. The monograph consists of an overview
chapter on the project, the history of previous work, and
the taxonomy and biogeography of Majungasaurus, a second
chapter on paleoenvironments and paleoecology by Ray
Rogers (Macalester College) and colleagues, four chapters on
the morphology of the beast, and a final chapter on skeletal
pathologies. The very heart of the monograph is a remarkable
70-page paper by Scott Sampson and Larry Witmer on
the craniofacial anatomy of Majungasaurus. Unlike Scott,
Larry Witmer (Ohio University) is no field paleontologist.
What you see on his hands is much more likely to be the
proverbial blood and guts of the anatomy lab rather than
good honest Cretaceous under the fingernails. Larry (who
happens to be my doctoral grandson, by way of David
Weishampel at Johns Hopkins) is a superb anatomist who
has based his career on using modern anatomical and medical
imaging techniques to probe deep recesses in the skulls of
modern reptiles, birds, and mammals to understand similar
structures in dinosaurs and other extinct archosaurs. Larry’s
particular gift to paleontology lies in CT scanning skulls,
thereby illuminating interior spaces within bones, including
pneumatic (air) spaces, vascular channels, and nerve canals.
He in effect reduces skulls to arrays of digital points that
28 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
can pirouette about the head of a pin, rotate in any plane,
tipping this way and that, and can be selectively colored in
ways to highlight any system of interest. His nondestructive
techniques allow specimens to be revealed as never before.
Understandably, Larry is much in demand as a highly valued
collaborator on many dinosaur projects involving cranial
anatomy – I am presently wooing him myself. Scott is a
fine descriptive anatomist himself, and their collaboration
yields excellent results. Never before has the morphology of
a theropod been presented in such stunning detail. It could
be noted that the bones of our skull, although disarticulated
and distributed over 2 m2 , were exceptionally well preserved
and nearly undistorted. In the Sampson & Witmer paper,
each bone is separately illustrated and compared with those
of relatives, including such taxa as Carnotaurus, Abelisaurus,
Rugops, and Ceratosaurus. Rarely has a specimen enjoyed such
dense documentation. There are “merely” 31 figures, but the
first ten have more than 100 images, including line drawings,
silhouettes, photographs, stereo pairs, and CT scans, and the
following figures continue in kind. For many specimens this
would be overkill, but the excellence of this material justifies
the effort. Just as one eye-catching example, Figure 17 (12
images) is a two-page presentation of the semitransparent
braincase of Majungasaurus, CT scanned in stereo pairs and
colorized in eight colors to emphasize pneumatic recesses,
brain tissue, vascular elements, and the bony labyrinth of the
inner ear. Few are the modern animals that are known in
such detail (apart from the crocodiles and birds that Witmer
has himself studied). In my teaching experience, I can
think only of the colorized air sinuses of domestic animals
presented by the German anatomists Nickel, Schummer, and
Seiferle. Most paleontologists are incapable of achieving such
consummate descriptive and analytical excellence.
A separate chapter of 23 pages is devoted to teeth by
theropod tooth expert Josh Smith (National Geographic
Society). Patrick O‘Connor covers the axial skeleton, ribs,
vertebrae, and chevrons in 35 pages. He packs in 22 figures,
consisting primarily of photographic plates. He pays attention
to pneumatization and vascularization of vertebrae. Matt
Carrano (Smithsonian Institution) describes the appendicular
skeleton in a compact 16 pages, illustrated primarily by
photos. The length of the chapter is consistent with the lesscomplete and less well-preserved nature of that portion of
the skeleton. Carrano, who has valuable expertise on South
American theropods, shows that the skeleton is rather stocky
and short limbed compared to Carnotaurus and to other
non-abelisaurid theropods. Finally, soon-to-finish Stony
Brook PhD student Andy Farke and O’Connor briefly survey
pathologies in Majungasaurus specimens, and these seem to
be concentrated on vulnerable extremities. They document
vertebral fusions and phalangeal anomalies. Truncation of
the tail seems to document an ancient mishap!
The Mahajanga Basin Project is a model for paleontology
today. It represents collaborative scholarship at the highest
level involving student training, young faculty, multiple
institutions, international cooperation, wisely targeted
government support, and cooperation of the Society of
Vertebrate Paleontology. Never have research funds been
so wisely invested. My highest kudos to David Krause,
Scott Sampson and all of their associates. I look forward to
continuing results for years to come.
Literature Cited
Curry, K. A. 2001. The Evolutionary History of the Titanosauria.
Unpublished PhD Dissertation, Stony Brook University,
Stony Brook, New York, 556 pp.
Curry Rogers, K. A., & C. A. Forster. 2001. The last of
the dinosaur titans: a new sauropod from Madagascar.
Nature, 412: 530-534.
Forster, C. A., L. M. Chiappe, D. W. Krause, & S. D. Sampson.
1996. The first Cretaceous bird from Madagascar. Nature,
382: 532-534.
Forster, C. A., S. D. Sampson, L. M. Chiappe, & D. W.
Krause. 1998. The theropod ancestry of birds: new
evidence from the Late Cretaceous of Madagascar.
Science, 279: 1915-1919.
O’Connor, P. M. 2003. Pulmonary Pneumaticity in Extant
Birds and Extinct Archosaurs. Unpublished PhD
Dissertation, Stony Brook University, Stony Brook, New
York, 304 pp.
Sampson, S. D., M. T. Carrano, & C. A. Forster. 2001. A
bizarre predatory dinosaur from the Late Cretaceous of
Madagascar. Nature, 409: 504-506.
Sampson, S. D., & D.W. Krause, eds. 2007. Majungasaurus
crenatissimus (Theopoda: Abelisauridae) from the Late
Cretaceous of Madagascar. Society of Vertebrate Paleontology
Memoir 8: 1-184.
Sampson S. D., L. M. Witmer, C. A. Forster, D. W. Krause, P.
M. O’Connor, P. Dodson, & F. Ravoavy. 1998. Predatory
dinosaur remains from Madagascar: implications for the
Cretaceous biogeography of Gondwana. Science, 280:
1048-1051.
Peter Dodson is Professor of Anatomy in the School of Veterinary
Medicine and Professor of Earth and Atmospheric Science in the
School of Arts and Sciences at the University of Pennsylvania.
His column is a regular feature of American Paleontologist.
Email [email protected].
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 29
A N A M AT E U R ’ S PE R S PE C T I V E
Explosions of Biodiversity
By John A. Catalani
In paleontology, when one speaks of explosions of
biodiversity, it is generally assumed that one is speaking of
the Cambrian Explosion. This is understandable because
this “initial” radiation in both morphological disparity
(range in utilized body plans) and diversity of taxa set the
stage for the subsequent players in the game of life on Earth.
However, we now recognize two other “explosions” in the
early history of life – one that occurred before the Cambrian
Explosion, named the Avalon Explosion (the time of origin
of the Ediacara Biota), and one after, called the Great
Ordovician Biodiversification Event (GOBE). Even though
the Cambrian Explosion gets most of the press, each of these
diversifications was significant for several reasons. First, they
occurred at or near the beginning of multicellular life and,
second, they (well, the last two anyway) determined the
shape (body plans) and evolutionary history (phylogeny) of
life on Earth, culminating in all that we see today – and that
is just plain cool.
The Ediacara “Biota” (some paleontologists do not like
the term “biota” because Ediacaran fossils vary widely in
size, shape, and construction) has been, since its discovery
in 1946 in Australia (although examples of the fauna were
found early in the twentieth century in Namibia), enigmatic
in terms of body-plan organization and relationships to
present-day organisms. The Ediacaran fossils occur in
rocks of the upper Ediacaran Period (see Catalani, 2005,
for background on this period) deposited approximately
575-542 million years ago (Ma) and have now been found at
dozens of localities across five continents. Forms range from
small (centimeter-size), somewhat amorphous blobs to very
large (meter-size) fronds and discs. The frond and disc fossils
reveal a structure quite unlike anything alive today. These
organisms consisted of a quilted surface sometimes described
as having an “air-mattress” morphology and, as far as can be
determined, lacked a mouth and gut. It has been proposed
that gas exchange (as well as food intake) in these organisms
occurred by diffusion through their external surface instead
of through internal surfaces as occurs in most animals today.
This unique morphological architecture led Adolf Seilacher
to propose that these animals were a “failed experiment” in
biological organization that had no analogue with presentday life forms. In several papers (Seilacher 1989, 1992), he
proposed that the Ediacaran organisms should be placed in
a separate phylum that he originally termed “Vendozoa” (the
Ediacaran Period has also been referred to as the Vendian)
and then later renamed it Vendobionta. The most recent
evaluation of the Ediacara Biota suggests that it consisted of
30 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
“a mixture of stem- and crown-group radial animals, stemgroup bilaterian animals, ‘failed experiments’ in animal
evolution, and perhaps representatives of other eukaryotic
kingdoms” (Narbonne, 2005: 421).
The Ediacara Biota, which appeared just after the end
of the Gaskiers glaciation (the last glaciation of the socalled “Snowball Earth”) and disappeared around the start
of the Cambrian Period, actually consisted of three distinct
assemblages (see Narbonne, 2005, for a much more detailed
description). The oldest (approximately 575-560 Ma) is
termed the Avalon Assemblage. Fossils show that these
organisms were constructed of modular elements forming,
among others, frond-shaped colonies that lived in deep water.
The shallow-water White Sea Assemblage (approximately
560-542 Ma) displayed the most diverse biota composed
of frond-shaped as well as segmented organisms. The Nama
Assemblage (approximately 549-542 Ma) also consisted
of shallow-water organisms but of relatively low diversity.
Speculations that attempt to explain the appearance and
diversification of the Ediacara Biota include the presence
of significant amounts of oxygen that reached deep water
for the first time, the Acraman bolide impact event (South
Australia), and the breakup of the supercontinent Rodinia.
In the most recent study of the Avalon Assemblage (and
one of the two new papers that provided the incentive for
this essay; the other concerns the GOBE and is detailed
below), Shen and colleagues (2008) compared the radiation
Reconstruction of the Ediacara Biota (courtesy of Joshua Sherurcij, via
Wikimedia Commons).
of body plans of the Ediacara Biota to that of the Cambrian
Explosion. They termed this rapid increase in disparity the
“Avalon Explosion” in which virtually the complete range
of Ediacaran body plans evolved in the Avalon Assemblage
and was maintained with little change in the two subsequent
assemblages. Taxonomic diversity, however, increased,
gradually reaching its peak in the White Sea Assemblage, then
decreased in the Nama Assemblage. The authors conclude
that “the marked parallels between the Cambrian and Avalon
explosions suggest that the decoupling of taxonomic and
morphological evolution is not unique to the Cambrian
explosion and that the Avalon explosion represents an
independent, failed experiment with an evolutionary pattern
similar to that of the Cambrian explosion” (p. 84).
The Cambrian Explosion (very approx. 542-520 Ma
although some researchers speculate that the actual “explosion” was compressed in time at around 530-520 Ma)
documented the initial emergence of life in its more-or-less
familiar form. During this radiation event, all but one of
the phyla that characterize life on Earth today made their
first appearance. From studies of trilobites, it appears that
variation in morphological form was particularly strong at
this time, leading to an explosion in disparity. As with the
Ediacara Biota, the process of innovation and diversification
of body plans was rapid at the beginning of the Cambrian
Explosion. Subsequent preening of body forms resulted in
many that became the foundation for succeeding animals as
well as some that, for one reason or another, did not survive.
Other studies suggest that at this time the rates of molecular
evolution were exceptionally high. Some paleontologists have
proposed that many of the morphological forms that arose
during the Cambrian Explosion cannot readily be assigned to
an existing phylum. This is not to say that they represent, as
proposed by Gould (1989), separate and distinct phyla, just
a period of experimentation in body form. Others maintain
that most of the problematic forms can be assigned to
existing phyla and that the morphological disparity evident
in the Cambrian is not much different than that seen today.
This also raises the question as to just what constitutes a
phylum, but I will defer that question to those much more
qualified than I. Be that as it may, it is obvious that there was
an unprecedented radiation of body forms at the expense of
taxonomic diversity during the Cambrian Explosion.
Several theories have been proposed to explain the Cambrian Explosion including high rates of molecular evolution
(as mentioned above), continued oxygenation of the oceans,
and the acquisition by animals of the ability to secrete hard
shells (biomineralization) in response to predation. It is also
probable that the seeds for the Cambrian Explosion were
sown well before the Cambrian Period and, therefore, before
the advent of biomineralization, which would have severely
limited the formation of recognizable fossils. Some have even
suggested that the “Cambrian Explosion” is merely an artifact
of the invention of biomineralized. That might be, but all of
Reconstruction of an Ordovician sea floor (courtesy of National Aeronautics and Space Administration, via Wikimedia Commons).
these diverse organisms had to radiate at some point and the
limited time available, geologically speaking, points to some
type of “explosion.”
Needless to say, although I am fascinated with the earlier
two “explosions,” the Great Ordovician Biodiversification
Event holds a special and intense interest for me because it
was during this time that my beloved nautiloids lived, died,
and were fossilized. The Ordovician (approx. 489-443 Ma)
radiation is different than either the Ediacaran or Cambrian
“explosions” for several reasons. First, the earlier two both
experienced a radiation of body plans, disparity, at the
expense of taxonomic diversity, whereas during the GOBE
only one new phylum, Bryozoa, originated but taxonomic
diversity increased dramatically. Second, the Ediacaran and
Cambrian radiation events were restricted in time, geologically speaking, with all groups diversifying at about the same
time for each event, whereas the GOBE radiations, although
occurring in definite pulses, were spread pretty much
throughout the entire Ordovician. Therefore, the origination
of most of the phyla and classes of animals, as well as a
varied set of body plans, in the Cambrian set the stage for
the Ordovician radiations to fill niche spaces with a diversity
of species. The GOBE, it is generally acknowledged, was
characterized by the greatest increase in biodiversity in the
history of life – there was a two-fold increase in taxonomic
orders, a three-fold increase in families, and a nearly four-fold
increase in genera (Webby et al., 2004: 9). Nautiloids, for
example, were represented at the beginning of the Ordovician
by only one order but, by the time the Late Ordovician
rolled around, had radiated into at least ten orders – nine of
which are represented in the Platteville rocks that I have been
studying and collecting for the past 30 years. Additionally,
nautiloids diversified into a wide range of shell shapes and
species and reached their all-time peak diversity at this time.
The potential of several groups that experienced their initial
radiations during the GOBE, however, was not fully realized
until long after the Ordovician. For example, the bivalves, a
group that would become an important component of postAMERICAN PALEONTOLOGIST 16(2) Summer 2008 31
Paleozoic faunas, evolved most of their shell forms during
the Ordovician radiations (many bivalves representing both
epifaunal and infaunal types are found in the carbonate rocks
of the Platteville alongside my nautiloids).
This lesser known event, when compared to the Vendian
and Cambrian explosions, finally received its due when a
monumental volume (Webby et al., 2004) was published that
covered all taxonomic groups, summarized environmental
and tectonic aspects of the Ordovician world, and defined a
global stratigraphic framework and a standard timescale that
allowed the taxonomic studies to be compared. Although
the time slices utilized by the book’s authors had been
determined using radiometric dating techniques, all of the
global stages still had not been officially named when the
volume was published. In 2007, however, the International
Subcommission on Ordovician Stratigraphy (ISOS) finally
agreed on a set of names for these global stages after almost
30 years of deliberation. Defining these units was complicated
by the highly provincial nature of Ordovician faunas, the
uneven occurrence and distribution of reliable radiometric
dates, and the search for appropriate type sections that would
suitably illustrate each stage. It is now possible to place local,
regional, and continental series and stage names into a global
32 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
context. Consequently, the Platteville rocks (which were
probably deposited in only 1-2 million years, by the way)
that contain the abundant and diverse molluscan fossils that I
collect are part of the Turinian Stage of the Mohawkian Series
(North American designation), the Caradoc Series (British
terminology still used as a point of common reference), and
the Sandbian Stage of the Upper Ordovician Series (global
designation). Comprehending the various terms that are
used to designate the same rock unit can be overwhelming
at first, but when placed on a chart, the hierarchical logic
becomes clear, or at least it does to those of us that are true
Ordovician geeks.
As stated above, the GOBE occurred in definite pulses of
radiations. Although the most intense diversification took
place during the Mid (when referring to a time series Mid
is used, when referring to a rock series Middle is used) to
Late Ordovician (a duration of around 28 million years),
taxonomic radiations lasted virtually the entire period (nearly
46 million years). Additionally, the GOBE was taxonomically
selective – some groups diversified robustly whereas others
experienced only moderate diversification. The first pulse of
radiations commenced slowly late in the Early Ordovician
then picked up dramatically early in the Mid Ordovician
until a plateau in diversity was experienced for the rest of
this stage. The second pulse followed this plateau with an
even greater rate of diversification during the beginning
of the Late Ordovician with peak diversity in the middle
of the Late Ordovician. A minor decline in diversity was
experienced after this peak. The final pulse occurred near
the end of the Late Ordovician when radiations again
increased dramatically reaching the highest diversity peak in
the entire Ordovician just before the end-Ordovician mass
extinction – an event second only to the end-Permian mass
extinction in severity. A post-Ordovician recovery initiated a
period of relatively stable diversity (the so-called “Paleozoic
Plateau”), broken significantly only by the end-Devonian
mass extinction, which lasted until the massive end-Permian
extinction event.
As with the other radiation events described above,
a plethora of possible causal factors have been proposed
to explain the GOBE. These factors include, but are not
limited to, intrinsic biological factors, increased volcanism
that resulted in an influx of continental nutrients into the
oceans, an areal increase in hard substrates, plate movements,
and escalation in the partitioning of marine habitats. Now,
in another recent paper, Schmitz and colleagues (2008:
49) suggest an interesting explanation for the onset of the
GOBE. The authors claim “that the onset of the major
phase of biodiversification ~470 Myr ago coincides with
the disruption in the asteroid belt of the L-chondrite parent
body – the largest documented asteroid breakup event during
the past few billion years.” The 470 Ma that they emphasize
corresponds approximately to the middle of the first GOBE
pulse – specifically, the Mid Ordovician increase in the rate
of diversification described above. The asteroid breakup,
they say, caused an elevated rate of meteorite bombardment
which lasted for 10-30 million years after the initial breakup.
Evidence, compiled from sections in Sweden and China, for
this event includes rocks enriched with an isotope of osmium
commonly found in meteorites, the recovery of unaltered
chromite grains with an elemental composition distinct
from terrestrial chromite, and the discovery of abundant
fragments of the meteorites that were incorporated into the
rocks that were laid down at this time. Additionally, from an
analysis of impact craters on Earth, it appears that “impacts
may have been more common by a factor of 5-10 during
the Middle Ordovician compared with other periods of the
Phanerozoic” (p. 52). The authors also compiled data on
fossil brachiopods contained in rocks of the same age from
Baltoscandia and concluded that, for this region at least,
the onset of the two events, meteorite bombardment and
brachiopod diversification, “seems to coincide precisely” (p.
52). It has been claimed by others, however, that the initial
diversification of the GOBE started before the sustained
bombardment.
So, how can impacts cause faunal diversifications instead
of the extinctions that are popularly presumed to have resulted
from them? It turns out that hard evidence for impact-caused
extinctions for all but the end-Cretaceous event is tenuous at
best. Apparently, there is a size threshold below which impacts
disrupt ecosystems but do not initiate mass extinctions.
Schmitz and colleagues state that “more minor and persistent
impacts could generate diversity by creating a range of new
niches across a mosaic of more heterogeneous environments”
(p. 52). In other words, the niche partitioning initiated by
the numerous impacts resulted in more diverse environments
that, in turn, fostered speciation events. Admitting that these
conclusions are speculative, the authors maintain that the
most reasonable explanation is that numerous and persistent
impacts caused modifications in Earth’s biota. This cause
and effect scenario is an intriguing possibility but has by no
means been proven – stay tuned for further developments.
I consider myself fortunate to have been exposed (no
pun intended) to Ordovician rocks when growing up. The
collecting that I began as a hobby has escalated into a passion
for the nautiloid (and other molluscan) fossils contained in
these rocks. Little did I know then that I was benefiting from
the results of the greatest taxonomic diversification in the
history of life on Earth. The nearly 60 species of nautiloids
that I have amassed over the years are a testament to this
unique event.
Further Reading
Catalani, J. 2005. Quo Vadis, Precambrian? American
Paleontologist, 13(2): 18-20.
Gould, S. J. 1989. Wonderful Life. W. W. Norton, New York,
347 pp.
Narbonne, G. M. 2005. The Ediacara Biota: neoproterozoic
origin of animals and their ecosystems. Annual Review of
Earth and Planetary Science, 33: 421-442.
Schmitz, B. et al. 2008. Asteroid breakup linked to the Great
Ordovician Biodiversification Event. Nature Geoscience,
1: 49-53.
Seilacher, A. 1989. Vendozoa: organismic construction in the
Proterozoic biosphere. Lethaia, 22: 229-239.
Seilacher, A. 1992. Vendobionta and Psammocorallia: lost
constructions of Precambrian evolution. Journal of the
Geological Society, London, 149: 607-613.
Shen, B., L. Dong, S. Xiao, & M. Kowalewski. 2008. The
Avalon explosion: eevolution of Ediacara morphospace.
Science, 319: 81-84.
Webby, B. D., F. Paris, M. L. Droser, & I. G. Percival. 2004.
The Great Ordovician Biodiversification Event. Columbia
University Press, New York, 484 pp.
John Catalani is retired from teaching science at South Hill
High School in Downers Grove, Illinois. His column is a regular
feature of American Paleontologist. Email fossilnautiloid@aol.
com.
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 33
EXTRA
Christopher Garvie Honored by Paleontological Research Institution
In March, PRI Director of
Collections Gregory Dietl (at right
in photo) presented the Katherine
Palmer Award for outstanding
contributions to paleontology by
a nonprofessional to Christopher
Garvie at the annual Mid-America
Paleontological Society Fossil Expo
at Western Illinois University in
Macomb, IL. The following was
read at the presentation.
Each Spring, the Paleontological
Research Institution is proud to
recognize a nonprofessional for
their contribution to the field
of paleontology by presenting
the Katherine Palmer Award,
named after PRI’s second
director, Katherine van Winkle
Palmer, who held avocational
paleontologists in high regard
and collaborated with many
during her long career. PRI has
presented this award almost every
year since 1993. We are especially grateful to Mid-America
Paleontological Society for providing us with this very special
opportunity to present this award over much of that time.
Christopher Garvie is a software engineer in Austin,
Texas, specializing in aerospace and manufacturing systems.
He was born in Aberdeen, Scotland, and grew up in
Hamburg, Germany, and London, England. He majored
in mathematics and physics at the University of Aberdeen.
While studying for his degree, Chris took a course in
geology and he credits that experience with setting him off
on a lifelong passion for fossils. He collected his first fossils
several years later while living in Seattle, which were Eocene
mussels from northwestern Washington State. Chris did not
know at the time that these mussels, which he still has in
his collection, would only be the tip of a very large iceberg.
Since that time, Chris has collected fossils from numerous
sites around the world. In particular, and very fortunately
for the field of paleontology, Chris ended up devoting a
large part of the last two decades (totaling more than 1,000
collecting trips) to exploring and (re)discovering the Eocene
strata of Texas. These efforts have resulted in his significant
contributions to the paleontology of the Paleogene of the
western Gulf Coast. His 1996 monograph, published in
PRI’s journal, Bulletins of American Paleontology, on the
34 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
molluscan macrofauna of the Eocene Reklaw Formation of
Texas stands as the most rigorous systematic documentation
of the Paleogene macroinvertebrate fauna of the Gulf Coast
since the classic monographic studies from the 1930s, 1940s,
and 1950s, including those by Gilbert Harris (PRI’s founder
and first Director) and Katherine Palmer. It is a fitting tribute
to Chris’s scientific contributions that his type specimens
from the Eocene of Texas are now housed in PRI’s collections
alongside those of these intellectual predecessors.
Chris’s personal collection consists of about 750,000
curated specimens in approximately 15,000 lots, particularly
from the Paleogene of the western Gulf Coast. His collection
is especially valuable as a resource to researchers working in
the Texas Paleogene. The collection also contains important
comparative material from the Paleogene of the eastern
Gulf and the Paris Basin, among other areas. Chris has also
unselfishly shared his wealth of knowledge about collecting
localities with visiting researchers and often has provided
unique specimens to paleontologists that would have
otherwise been unknown to science.
It is with great pleasure that the PRI presents the 2008
Katherine Palmer Award in recognition of outstanding
contributions to paleontology by a nonprofessional to Chris
Garvie.
T H E N AT U R E O F S C I E N C E
The Egg, the Chicken, and the 300 Million Years in Between
By Richard A. Kissel
It’s a new day. The sun appears from beyond the horizon, and
of Bayn Dzak yielded a different secret. Entombed in the
as the cool of the previous night quickly retreats, a swampy
sandstone were not the remains of human ancestors, but the
forest comes alive. The sound of fluttering insect wings fills
first dinosaur eggs known to science. Skeletal trophies erected
the hot, humid air. Scampering among rotting logs, tiny
in New York and elsewhere might have displayed dinosaurs’
amphibians make an occasional splash. And towering above
massive forms, but the newly unearthed, 75-million-year-old
all, the leaves of enormous trees – some 150 feet high – rustle
eggs provided a glimpse into the lives of these ancient oddities
in a faint breeze. Welcome to Nova Scotia, 300 million years
that no skeleton could: they revealed the babies behind the
ago. The continents, always on the move, are slowly gathering
beasts.
to form a single landmass. Stretching from pole to pole, this
Since the Gobi expeditions, fossilized dinosaur eggs
supercontinent is dominated by massive glaciers to the south.
have been recovered from sites around the world. In rare
But here, along the equator, these lush forests thrive. It is here
instances, embryos have even been found within eggs. From
that life will change forever.
egg to elder, the life history of a
The study of ancient life –
dinosaur is slowly unraveling with
paleontology – explores four
each discovery. The most recent
billion years of evolution. Across
report of significance described a
this unfathomable span of time,
clutch of six eggs, five of which
an untold number of species
contained embryos. Discovered
evolved, thrived, and then
in South Africa, the embryos are
disappeared under the inevitable
thought to have belonged to the
cloud of extinction. Fossils are
prosauropod
Massospondylus.
the only record we have of their
An often overlooked group of
existence; relics of bygone eras,
dinosaurs, prosauropods are
they provide scientists with the
closely related – if not ancestral
evidence necessary to unfurl
– to those icons of prehistory, the
and begin to understand this
sauropods. Giants among giants,
tapestry of ancient life. And of
sauropods are characterized by
the countless species that have
their extremely long necks and
inhabited Earth during the past
long, heavy tails, with famous
four billion years, none have
members of the group including
captured the imagination more
Apatosaurus, Diplodocus, and
than those fantastic reptiles of
Brachiosaurus. Like sauropods,
The amniotic egg (al, allantois; am, amnion; ch,
the Mesozoic Era: the dinosaurs.
prosauropods were herbivorous,
chorion; em, embryo; sh, outer shell; y, yolk sac).
People of all ages can often
and they too carried relatively long
recognize the horned Triceratops,
necks and tails. They probably
the meat-eating Tyrannosaurus, and – with its rows of plates
also possessed the ability to rear upon their hind legs and
and spikes – the lusus naturae that is Stegosaurus. Seemingly
move about, a feat unlikely for any sauropod. First appearing
plucked from some twisted, Seuss-ian nightmare, dinosaurs
around 230 million years ago, prosauropods were among
dominated the Mesozoic Era – that fraction of Earth’s history
the earliest dinosaurs to walk the Earth. The fossils from
from 250 to 65 million years ago – and their fossilized remains
South Africa, dating to 190 million years ago, are the oldest
have fascinated the human mind for centuries.
dinosaur eggs and embryos known to science.
In 1922, a team from the American Museum of Natural
Animals of all sorts lay eggs, of course, from frogs to fishes
History in New York set out on what would ultimately be
to insects. But those laid by dinosaurs are a special type of
one of the most celebrated expeditions in the history of
egg, an amniotic egg. Like most structures that pass before
paleontology. Carried by automobiles and accompanied by
the eyes of comparative anatomists, amniotic eggs are defined
trains of camels saddled with supplies, the troop scoured
by their parts, and in this particular instance, those parts are
the Gobi Desert in search of, it was hoped, insight into
a series of fluid-filled membranes: the amnion surrounds
the origins of humankind. But in 1923, the Flaming Cliffs
the embryo; the yolk sac contains food for the embryo; the
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 35
allantois stores waste; and the chorion surrounds all of these
membranes, helping to hold the egg’s contents together. But
perhaps the most distinctive property of the amniotic egg is
the outer shell. Whether mineralized and hard or leathery
and more flexible, this shell provides not only protection, but
it prevents the developing embryo from drying out. Animals
that possess this type of egg are called, collectively, amniotes,
and all amniotes fall into one of two groups: they are either
synapsids, or they are reptiles.
Today, reptiles consist of the familiar – turtles, lizards,
snakes, and crocodiles – but the group’s evolutionary
history includes many lineages, the most famous of which
is, of course, the dinosaurs. From bed sheets to Burroughs,
dinosaurs have invaded every niche of pop culture, and they’ve
been synonymous with the term extinction for decades. But
recent years have witnessed an almost embarrassing wealth
of fossil evidence that links dinosaurs and birds, and it is
now clear that birds evolved from a lineage of small, meateating dinosaurs. In a strict scientific sense, birds are living
dinosaurs, and because dinosaurs are reptiles, so are birds.
Another reptilian lineage is that of the pterosaurs. While
dinosaurs dominated the land, these flying reptiles darkened
Mesozoic skies, their leathery wings supported by elongated
hand and finger bones. Long before the very first dinosaurs,
pareiasaurus and other groups of bizarre reptilian wonders
inhabited the lands 260 million years ago. Possessing stocky
frames and skulls marred by unfortunate pits and protrusions,
pareiasaurs were imposing beasts, but with teeth well suited
for snipping leafy bites, these giants were gentle. Lizard-like
captorhinids were a common site 280 million years ago, as
were mesosaurs: small reptiles that used long, flat tails and
broad feet to swim after their prey. These groups represent
a mere taste of reptilian diversity throughout the ages, with
many more lineages long lost to extinction.
Synapsids possess a similarly complex history, but only
one group survives to the present day: mammals. The vast
majority of today’s mammals, including humans, obviously
do not lay eggs, but they are amniotes. Over time, the outer
shell and yolk sac have been suppressed and other membranes
modified, resulting in live birth within most species. Only
the platypus and echidnas remain as delightful reminders
of all mammals’ primitive, egg-laying roots. The very first
mammals, their story told through fossilized teeth and little
else, evolved early in the Mesozoic Era, around 210 million
years ago. They entered the world alongside the earliest
dinosaurs, and they would live in the shadows of those ruling
reptiles for the next 150 million years. Immediately ancestral
to mammals were a lineage of cynodont synapsids; heels and
a bony palate separating the nasal passage from the mouth
are only two of the characteristics that these cynodonts
passed down to their mammalian descendants. Prior to
the Mesozoic Era, synapsids were extremely diverse. Some
260 million years ago, saber-toothed gorgonopsians were
lethal predators and the dinocephalians sported grotesque
skulls adorned with horn-like knobs or thick bony plates.
Around 280 million years ago, synapsids were represented by
the great sail backs and their kin. Appearing more reptilian
than mammalian at first glance, with their sprawling limbs
and long tails, sail backs like Dimetrodon have achieved
considerable celebrity within the prehistoric bestiary, but
more often than not, they are sadly mistaken for (and
labeled as) members of the very reptilian, very unsynapsid
The amniote family tree consists of two branches: reptiles (top) and synapsids (bottom). Reptiles shown are (left to right) an early form
like Hylonomus, a pterosaur, and a dinosaur; synapsids include a sail back, an early cynodont, and a mammal. To suggest that this
diagram is a simplified representation of these two branches is a gross understatement. The evolutionary histories of both reptiles and
synapsids are extremely rich, with a wealth of varieties evolving and falling to extinction during the past 300 million years. Reptile and
synapsid illustrations from C.L. Fenton’s Animals of Ancient Lands (1922) and The Age of Mammals (1923).
36 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
dinosaurs.
Taken individually, the evolutionary histories of reptiles
and synapsids are incredible stories of survival, adaptations,
and extinction, but examined under the same lens, they
take on an even greater meaning. As they are traced back
through time, it is found that these two histories do not run
parallel to one another; instead, they slowly converge to a
single point. This point represents the very first amniote, and
it is the single ancestor that gave rise to all later of its kind,
from dinosaurs and crocodiles to sail backs and mammals,
including humans. In paleontology, claims of first or oldest are
guaranteed headlines in both popular and scientific literature,
and for good reason. It is the attempt of paleontology to
answer questions about life’s history, and perhaps the greatest
question of all is that of origin. So, where – and when – did
that very first amniote appear?
In 1842, Sir Charles Lyell first visited the rocky cliffs at
Joggins, Nova Scotia. Located along the shores of the Bay of
Fundy, the area is known to most for its great tides, which are
among the highest in the world. But Lyell – often regarded
as the father of modern geology – immediately recognized
perhaps an even greater significance. Exposed along grand seacliffs, the rocks at Joggins date to the Carboniferous Period,
some 300 million years ago, and entombed within them is an
incredible window into a lost world. Fossilized tree stumps
and trunks, preserved upright as they would have appeared in
life, tell the story of dense forests composed of towering trees,
including the 150-foot-tall Lepidodendron. Giant horsetails
called Calamites reached heights of 30 feet. And along the
forest floor, vine-like Sphenophyllum crept along. Bordering
a shallow sea, these swampy forests were home to a parade
of animals. Dragonfly-like megasecopterans buzzed through
the air. Below, as evidenced by muddy trackways since turned
to stone, the millipede-like Arthropleura wound its sixfoot-long body through the undergrowth. Tetrapods, those
backboned animals with four limbs and digits, also called
this forest home, with amphibians like the salamander-like
Dendrerpeton living in and around the pools. All told, fossils
of some 150 species have been described from the fossilbearing deposits at Joggins, and these deposits rank as one
of the most celebrated Carboniferous localities in the world.
They provide a snapshot of a primeval forest and the animals
that dwelled within it.
But among the wealth of fossils produced from Joggins,
the most significant are those of a foot-long tetrapod named
Hylonomus. Lacking any spectacular sails, spikes, bumps, or
plates, Hylonomus at first appears deserving of little fanfare, but
its skeletal characteristics speak to its true nature: Hylonomus
is a reptile. Also recovered from Joggins are the remains
of another small tetrapod, Protoclepsydrops. As is too often
the case in paleontology, the specimens of Protoclepsydrops
are fragmentary and of poor quality, so determining the
true nature of the beast is therefore quite difficult. Early
reports identified Protoclepsydrops as a synapsid; if so, it is
the evolutionary sister of Hylonomus. But that assignment is
in question, and Protoclepsydrops might actually have been
a reptile. Future discoveries could ultimately provide new
insights into the true affinity of Protoclepsydrops, but until
that time, its exact position of on the amniote family tree
remains a mystery. That of Hylonomus does not. Hylonomus is
a reptile, and – dating to 300 million years ago – it is not only
the oldest known reptile, it is the oldest known amniote. The
very first amniote – the ancestor of all reptiles and synapsids
– was no doubt an animal like little Hylonomus.
Despite its humble beginnings, the amniotic egg would
ultimately change the landscape forever. Among tetrapods,
there are two basic types: the amniotes and the amphibians.
As their name implies, amphibians possess a double life; they
possess two major stages within their development. Adult
forms usually live on land, but their eggs are laid in wet or
moist environments and the initial stages of development
outside the egg occur in water. Lacking a protective shell, the
eggs of amphibians would simply dry out if not laid in water,
killing the embryo inside. As a result of this developmental
history, it is a biologic rule of sorts that amphibians are
restricted to wet or moist environments. The eggs of amniotes,
with their outer shell, are much more resistant to desiccation
than are those of amphibians, allowing amniotes to lay their
eggs on dry land, far from any water. This freedom allowed
the earliest amniotes to venture farther inland than their
amphibious contemporaries, and by the early stages of the
Permian Period, some 280 million years ago, amniotes had
spread to many corners of the globe. This diversification
continued throughout the Permian, with amniotes like the
gorgonopsians and pareiasaurs, and into the Mesozoic Era,
with dinosaurs and mammals taking center stage. After
the Mesozoic, all dinosaurs except birds vanished, leaving
mammals to fill niches left behind. And some 8 million years
ago, one type of mammal – a type of ape, specifically – stood
upright and walked the grasslands of Africa, beginning the
human story.
Today, more than 20,000 amniotes are known to inhabit
the Earth. They exist on every continent, and they’ve taken
on an incredible diversity of shapes, sizes, and lifestyles.
With its protective shell, the amniotic egg represented a key
innovation among tetrapods, permitting them to break their
reproductive ties to water and colonize all parts of the world.
Not long after his visit, Lyell referred to the shores of Nova
Scotia as a “most wonderful phenomenon.” Here, the great
sea-cliffs at Joggins record one of the most significant events
in the history of life’s evolution. Here, within swampy forests,
a new type of life had evolved. Here, then, is the reigning
birthplace of the amniotic egg.
Richard Kissel is the Director of Teacher Programs at Paleontological Research Institution. His column is a new regular feature
of American Paleontologist. Email kissel@museumoftheearth.
org.
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 37
BOOK REVIEW
Principles Updated
By Christopher A. McRoberts
Principles of Paleontology, 3rd edition, by M. Foote & A. I.
Miller, W. H. Freeman, 480 pp., ISBN 978-0-7167-0613-7,
$73.96 (hardcover), 2007.
Undergraduate paleontology courses are taught along a
continuum of pedagological approaches that range from
descriptive survey, tip-toe-through-the-phyla courses, in
which students memorize the names, morphology, and
stratigraphic significance of major
fossil groups, to principles courses
in which fossils as data are used to
address paleontological questions.
This later approach can be traced to
1970, when David Raup and Steven
Stanley introduced the first edition
of Principles of Paleontology. The
first edition of Principles was a grand
departure from traditional texts into
what David Meyer referred to as “a
new adaptive zone for paleontological
textbooks.” Beyond doubt, this
landmark text has transformed
and inspired a generation of
paleontologists. The 30 years since
the last edition of Principles have
seen great growth and advancement
in nearly all aspects of our science,
and this third edition of Principles by
Michael Foote and Arnold Miller is
a long overdue and forward-looking
update.
Although Foote and Miller have retained much from the
earlier editions of Principles, there are substantial changes
in both organization and content that reflect advances
in our discipline and the conceptual and methodological
framework in which we gather and interpret paleontological
data. Throughout the book, the authors emphasize and
utilize many of the advances in quantitative approaches to
fossil applications. The book is organized into ten chapters,
with a glossary, a bibliography, and a substantial index.
Additionally, the inside front cover has a geological time
scale chart and the inside back cover has a classification,
and a key of sorts, of organisms that have important fossil
records. There are numerous boxed features where specific
methods, examples, and/or topics are developed more fully.
Each chapter concludes with supplementary reading and, in
some cases, a list of available computer applications relevant
38 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
to the chapter contents.
As in the previous editions, the book starts where it
should – on the nature of fossils and the fossil record. This
chapter delivers the first principle in any paleontology course:
the various modes of fossil preservation and the quality of
the fossil record including its potential biases. The section
on taphonomy, which includes a substantially updated
discussion on time-averaging and a feature box on livedead comparisons, is a particularly
noteworthy addition. Also covered is
a worthy discussion on completeness
in the fossil record and methods for
estimating diversity from samples.
The last sections of chapter one
discuss temporal changes in the
fossil record and a survey of how our
understanding of diversity metrics
have changed over the past 100
years.
Chapter two, on growth and
form, covers the various growth
strategies of organisms and methods,
largely statistical, used in analyzing
shapes, characters, and growth
metrics. New to this edition are the
multivariate techniques employing
landmark analyses pioneered by
F. Bookstein and R. Rayment and
others in the 1980s and 1990s.
Chapter two also expands upon
theoretical morphology (which is given special treatment
later in chapter five), allometry, and heterochrony – areas
that have advanced substantially since earlier editions of
Principles.
Chapter three deals with populations and species and
introduces evolution, which is further developed in later
chapters. Species concepts, both biological and morphological,
are introduced, as are geographical and temporal models
of speciation. Although there is a feature box on genetic
differences between populations, the authors largely focus on
form-based methodologies including traditional descriptive
statistics and a new section on multivariate approaches
(including principal components and cluster analysis), most
useful for species discrimination among fossils.
Systematics (the relationships among organisms) and
taxonomy (describing, classifying, and naming organisms) are
discussed in chapter four. This chapter is a mix of traditional
aspects of naming, describing and revising species. The
discussion on higher taxa is largely relegated to the section on
phylogenetics. Much of this chapter is essentially new material
on evolutionary inference and taxonomic hierarchies with
an expanded section on phylogenetics emphasizing cladistic
methodologies. Other techniques of particular significance
to specialists deeply embroiled in taxonomic methodologies
(e.g., construction of temporally constrained phylogenies that
include fossil taxa and stratocladistics) are also covered.
Chapter five on evolutionary morphology encompasses
adaptation, and functional and theoretical morphology.
Expanding on the previous edition of Principles, this chapter
covers many new examples and methodologies. Yes, Raup’s
classic coiling models remain, but other examples including
the biomechanics of trilobite eyes and dinosaur locomotion,
and the theoretical morphology of bryozoan colony
growth are provided. Most interesting is the discussion on
morphological optimization and the relationships between
form and environment with respect to adaptation.
Chapter six on biostratigraphy is an expanded examination
of graphical and quantitative methods for correlation and
sequencing of biostratigraphic events. Included are a nice
how-to for Shaw’s method of graphic correlation, and
separate feature boxes on more relatively new (and perhaps
a bit too advanced for most undergraduates) techniques
including appearance-event ordination (AEO), constrained
optimization (CONOP), and ranking and scaling (RASC).
This chapter also presents a good summary of the relationships
between depositional sequences and the stratigraphic
distribution of fossils. It concludes with a feature box on
confidence limits on stratigraphic ranges.
Chapter seven deals with evolutionary rates and trends.
Much of the chapter involves morphologic change within
lineages and continues with a section on taxonomic rates of
evolution. There are several useful feature boxes in this chapter
including one on survivorship curves and one on estimating
taxic rates with incomplete sampling. The middle part of
the chapter deals with the tempo and mode of evolution – a
topic that relied heavily upon G. G. Simpson’s ideas in the
previous editions of Principles. This heavily revised section
includes species selection, species sorting, and punctuated
equilibria using Alan Cheetham’s classic study on Neogene
bryozoans as an example. The last part of the chapter deals
with evolutionary trends (directed speciation, and trends
resulting from differential speciation and extinction rates)
and provides a nice segue into the next chapter.
Chapter eight represents a substantially revised and
updated discussion on diversity dynamics and extinction.
Jack Sepkoski’s familial and generic database [Ed: available
from PRI publications, see http://www.priweb.org] serves
as the basis for the discussion on diversity curves and the
decline in origination and extinction rates. Of particular
note is the discussion on the Pull of the Recent and the
three evolutionary faunas of Sepkoski. Separate feature
boxes provide detail on constructing diversity curves and
mathematical modeling of the coupled logistic diversification.
The nature of mass extinctions, including intensity, rates,
selectivity, evolutionary significance, and their potential
causes, are also given sufficient coverage. Taxonomic and
occurrence databases figure prominently toward the end
of the chapter, which concludes with examples from The
Paleobiology Database (PBDB) and Neogene Marine Biota
of Tropical America (NMBTA).
Rather than separate chapters as in the previous edition,
paleoecology and paleobiogeography are combined in chapter
nine. This is somewhat unfortunate because I find there are
plenty of interesting applications and new examples in both
areas. Gone from the previous edition (and in my view,
missed) are the topics of living habits and limiting factors
in the distribution of marine organisms, and to some extent
population paleoecology. The section on paleoecology includes
a substantial discussion on numerical approaches in identifying
paleocommunities and in gradient analyses. A bulk of the
paleoecology section falls within evolutionary paleoecology
and addresses long-term trends in guild structure, tiering,
onshore-offshore patterns, and paleocommunity stability
(coordinate stasis). Also included are what are referred to as
“new approaches to paleoenvironmental and paleoclimatic
reconstruction” with examples using stable isotopes in
fossil clams and stomatal densities in fossil leaves. The part
of the chapter that directly discusses paleobiogeography is
substantially shortened from previous versions of Principles
and seems a bit of an afterthought. The authors recognize the
change in emphasis, noting their impression that there has
been a conceptual shift from more traditional paleoecological/
paleobiogeographic studies to those with more of a focus on
evolutionary paleoecology.
Concluding the book, chapter ten stresses the interdisciplinary nature of much of our science and provides case
studies and expanded discussion of four critical events in the
history of life: (1) the Cambrian explosion, (2) the late Permian
extinction, (3) the Paleocene-Eocene thermal maximum,
and (4) the Pleistocene megafaunal extinctions. Each of
these examples draws together concepts and methodologies
presented earlier in the text and provides readers with
questions and the current state of knowledge surrounding
each event. The chapter concludes with emerging directions
in paleontology with sections on conservation paleobiology
and astrobiology.
This book has much to recommend it. Foote and Miller
are excellent writers who speak from a wealth of experience
and authority in quantitative approaches to paleobiological
questions. The book is very readable – the text flows
quite naturally and is, at least from my reading, free from
grammatical and typographical errors. The book is very well
produced and very well illustrated with high-quality blackand-white and grayscale photographs. The extensive glossary
and index are useful. There are, however, a few areas that
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 39
could have been more fully investigated. I find it somewhat
remarkable that the authors essentially neglect trace fossils
(granted, this too was barely mentioned in the earlier
versions) whose application, especially in paleoecology and
ancient environments is paramount. Many readers will find
that coverage of vertebrate paleontology and paleobotany is
also limited.
I most highly recommend this book for instructors
who teach a principles/applications course, for those whose
courses are split (lab components on organisms, lectures
on principles), or others whose interest lies in current and
future directions on paleobiological research. Students will
benefit more from this book if they have under their belt
an organism-based paleontology course, thus freeing them to
explore the many exciting aspects of our science outlined in
this excellent book.
Christopher McRoberts is a Professor in the Geology Department at the State University of New York at Cortland, New
York. Email [email protected].
40 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
BOOK REVIEW
And Then There Was One
By Nan Crystal Arens
The Last Human: A Guide to Twenty-Two Species of Extinct
Humans, created by G.J. Sawyer and Viktor Deak, Yale
University Press, 256 pp., ISBN 978-0-30010-047-7, $45.00
(hardcover), 2007.
I believe that my pain is singular,
The pain of birthing and of dying.
But there are four billion of me,
Seeing birth, seeing death.
And our foremothers and their foremothers,
Smelling birth, smelling death,
Sometimes in the same breath.
Regressing in an unbroken chain,
Tasting birth, tasting death.
Until we meet the others.
Do they know death?
I know that they do.
The first foremother told me.
She saw it in their eyes:
The pain of birthing and of dying.
Science and art are siblings, born of the
same human creativity. Commonly, they
see the world in very different ways.
But sometimes, their common heritage
allows a synergy that transcends what
either alone can offer. So it is with The
Last Human.
The art struck me first, beginning
with the reconstructed face of Lucy – an
Australopithicus arfarensus who lived approximately three
million years ago – on the dust jacket. Her worried stare
is the product of the Fossil Human Reconstruction and
Research Team at the American Museum of Natural History
in New York, the creators of this volume. Using the science
of facial reconstruction, they have restored the distorted and
fragmentary skulls of 22 species of ancient humans, layering
them with muscle, fat and skin. Then the artist’s gentle hand
colored the skin, applied the hair, and crafted an expression
that looks simultaneously strange and familiar. Placed with
a natural backdrop, lit and photographed, the creatures
challenge the viewer to meet them as individuals, living and
sentient, rather than as numbered fossils in a drawer, bars
on a range chart, or termini on a phylogenetic tree. The face
of Paranthropus aethiopicus bubbles with whimsey. And the
Taung Child’s (Australopithecus africanus) Mona Lisa smile
moved me as I remembered the youngster’s fate: leopard
lunch.
But the images tell only half of the tale. Each species
has a back story, a brief, fictional narrative – based on fossil
evidence – that captures a moment in the life of the figured
creature. Some are heartwarming, like the tale of Homo
rhodensiensis and his son collecting honey and sugarplum
seeds during a long walk in the moimbo woodland. Others
terrifying, like the young female Paranthropus robustus who
fights bravely and in vain to free
her brother from the clutches of
a hungry leopard. From others
I recoiled in disgust. A Homo
heidelbergensis hunter murderes
his father-in-law in cold blood
and without remorse. A Homo
neanderthalensis boy watches his
family hunted down, butchered
and consumed by “little faces”
(Homo sapiens), and never fully
recovers. The stories are not
great literature, but they are
unrelentingly real, vivid, and
unromantic. Once again, I am
reminded that these were living,
thinking, feeling creatures, not
merely wax statues in a museum’s
echoing halls. And that is the
point.
Although
the
art
is
spectacular – reason enough to
spend a lot of time with this book – its triumph is science.
The authors have gathered together a dispersed literature and
unpublished information to complete each entry. For each
species, they synthesize current knowledge about (1) skull,
teeth, and diet, (2) skeleton, gait, and posture, (3) fossil sites
and possible range, (4) age, (5) tools, (6) associated animals
and habitats, (7) climate, (8) classification, (9) historical notes,
and more. Rather than merely reporting, they critique each
point. For example, I remember reading with interest the first
reports of seven-million-year-old Sahelanthropus tchadensis
(Brunet et al., 2002) discovered in central Africa. The
creature’s describers claimed that the position of the foramen
magnum suggested a bipedal gait. (The foramen magnum is
the opening in the skull into which the spinal column inserts.
In bipedal hominids, this opening is on the bottom of the
skull, allowing the head to balance atop a vertical spine. In
quadrupedal apes, the foramen opens toward the back of the
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 41
skull.) Sawyer and colleagues dismiss this claim curtly, saying
that a single skull, without limbs, hands or feet, is insufficient
to support such a conclusion (a conclusion quantitatively
confirmed by Wolpoff et al., 2006).
The discussion of locomotion in Australopithecus afarensis
was even more interesting. Typified by the nearly complete
skeleton nicknamed “Lucy” and the more recently discovered
Dikika infant, this creature has long been the archetype of
early bipedalism. Australopithecus afarensis had a human-like
pelvis and limb-joint angles that seem to offer conclusive
proof that it walked upright most of the time. This species
is also commonly linked to the Laetoli foot prints, three
bipedal hominid trackways found in the lower marker #7
tuff in Tanzania. However, a closer look reveals some skeletal
features more like those of modern baboons than Homo
sapiens. For example, the ratio of arm, leg, finger, and toe
bones shows that A. afarensis had forsaken the trees for life
on the ground, as have baboons. However, the A. afarensis
ratios differ significantly from bipedal Homo. Furthermore,
Lucy had thick upper arm bones and a relatively weak lower
back, suggesting that she supported her weight with her arms
most of the time. This level of critical evaluation illustrates
two important truths in science: things are not always as they
first seem and there is still a lot we don’t know.
This discussion, although fascinating, highlights a
quibble that I have with this book. It lacks citations and
references. The short list of suggested reading at the volume’s
end is aimed at the interested layperson. This book is rich
enough for the student and specialist. My desire to dive into
the primary literature supporting some of the narrative’s
mysteries was frustrated. There are a few clues in the text –
the occasional author or publication year. But, in general, the
sources remain as much a mystery as Australopithecus’ stance.
Another quibble: the text is poorly copyedited. This is most
surprising from Yale.
The reaction of my sophomores and juniors when I
brought the volume to Earth History class was even more
thought provoking. They were simultaneously fascinated
and repelled by the book’s vivid images. They were drawn to
the eyes, the faces, the expressions. Those eyes are filled with
sentience – they are human. But then the mate recognition
wiring of my nineteen-year-old students kicked in and they
recoiled from creatures who were family, but not really us. That
wiring likely exists because we have not always been alone. In
fact, for much of hominid history, several species have shared
the planet. During our own species’ short lifetime, we shared
our habitat with as many as six other close relatives (Figure
1). Growing evidence suggests that we could have shared the
forests of Flores in Indonesia with a very different member of
our family tree, Homo floresiensis, “the Hobbit,” as recently as
12,000 years ago. This is just a blink of an evolutionary eye.
Is it any wonder that a vestige of the repulsion of the “other”
lurks just under our swollen and wrinkled cortex?
And that is the point of this book. We, as a species, have
42 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
Figure 1. Ranges of the twenty-two species of fossil hominids. Data
extracted from discussions of age and fossil localities in the text. Solid
bars represent radioisotopically bracketed age ranges. Dashed lines are
biostratigraphically determined ages based on fossil animals found in
association with the hominids.
inherited our gentleness, our savagery, our cleverness, our
fear, our loyalty, and our stubbornness from those that came
before. It is like clearing out our parents’ home after their
death. We wish that we could find only the noble and the
good among the brick-a-brack, but we must deal with it all.
And then we must come to terms with the reality that we are
now alone.
References
Brunet, M., F. Guy, D. Pilbeam, H. T. Mackaye, A. Likius,
D. Ahounta, A. Beauvilain, C. Blondel, H. Bocherens,
J.-R. Boisserie, L. De Bonis, Y. Coppens, J. Dejax, C.
Denys, P. Duringer, V. Eisenmann, G. Fanone, P. Fronty,
D. Geraads, T. Lehmann, F. Lihoreau, A. Louchart, A.
Mahamat, G. Merceron, G. Mouchelin, O. Otero, P.
Pelaez Campomanes, M. Ponce De Leon, J.-C. Rage, M.
Sapanet, M. Schuster, J. Sudre, P. Tassy, X. Valentin, P.
Vignaud, L. Viriot, A. Zazzo, & C. Zollikofer. 2002. A
new hominid from the Upper Miocene of Chad, Central
Africa. Nature, 418: 145-151.
Wolpoff, M. H., J. Hawks, B. Senut, M. Pickford, & J.
Ahern. 2006. An ape or the ape: is the Toumaï cranium
TM 266 a hominid? PaleoAnthropology, 2006: 36-50.
Nan Crystal Arens is Associate Professor in the Department of
Geosciences at Hobart & William Smith Colleges in Geneva,
New York. Email [email protected].
New at the Museum of the Earth Store
True Story! DinoMummy $18.95
Locally Made! Wooden Cecil w/Devonian Base $30.00
Visit the Museum of the Earth Store on
Trumansburg Road (Rte. 96) in Ithaca, for these
exciting items and much, much more.
Or order by phone by calling 607-273-6623,
ext. 33, and one of our Museum Associates will
help you. A $5.00 flat fee will be added to all
phone orders to cover shipping and handling.
Puzzles for Ages 3 and up
Dinosaur Chunky Puzzle $12.00
Prehistoric Sunset Wooden Jigsaw $10.00
AMERICAN PALEONTOLOGIST 16(2) Summer 2008 43
Celebrate a wedding
Mark the birth of a child
Memorialize a love lost
Make your memory last by
adopting a piece of time
C) Barbara Page
Rock of Ages Sands of Time is a
remarkable mural in the Museum of the
Earth by artist Barbara Page. Made up of
544 tiles, the mural explores the history
of life from the Cambrian explosion to
modern-day humans. You can adopt one
of these tiles for $1,000 and name it in
honor of yourself, a special someone, or an
important event. Supporters receive a print
of their tile signed by the artist.
For more information
or to choose your tile, contact:
607.273.6623 x11
[email protected]
http://www.museumoftheearth.org/pgs/
adoptatile.php
mcut herem
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44 AMERICAN PALEONTOLOGIST 16(2) Summer 2008
On Exhibit at the Museum of the Earth
June 21 - September 21, 2008
Cloth $49.00
WORLDS BEFORE ADAM
The Reconstruction of Geohistory in the Age of Reform
Martin J. S. Rudwick
Picking up where Rudwick’s celebrated Bursting the Limits of Time leaves off, Worlds Before
Adam takes readers from the post-Napoleonic Restoration in Europe to the early years
of Britain’s Victorian age, chronicling the staggering discoveries geologists made during the
period: the unearthing of the first dinosaur fossils, the glacial theory of the last ice age, and
the meaning of igneous rocks, among others.
The University of Chicago Press
www.press.uchicago.edu