G404 Geobiology
Origin of Tetrapods
and life in the Carboniferous
and Permian
Reading: Benton
Chapters 4 and 5
Eurypos , early Permian temnospondyl (painting by Douglas
Henderson, 1990)
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Tetrapoda: vertebrates more closely related to living
amphibians and amniotes than to their nearest living
relatives
Derived tetrapods
Icthyostega
Crown
Tetrapoda
Acanthostega
Eusthenopteron
Stem
Tetrapoda
Osteolepis
Dipnoans (lungfish)
Coelocanths
Actinopterygia
Crown coelocanths
and dipnoans
Pandericthyes
Phylogeny of Bony Fish
Tetrapoda
Sarcopterygia
Osteichthyes
After Coates and Ruta, 2007. Fins into Limbs.
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Derived tetrapods
Icthyostega
Acanthostega
Pandericthyes
Eusthenopteron
Osteolepis
Dipnoans (lungfish)
Coelocanths
Actinopterygia
Synapomorphies
• reduction to five digits
• carpus and tarsus
• up to eight digits
• broad contact between jugal and quadratojugal
Tetrapoda
• flattened head
• enlarged ribs
• humerus with anterior keel for muscle attachment
Sarcopterygia • muscular pectoral and pelvic limbs with substantial limb bones
Osteichthyes
• one or more squamosal bones
• one or more splenial bones
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Transformation of the
limb during origin of Tetrapoda
Transformation of early tetrapod limb
involves modification of bones, loss of some
bones, addition of other bones
Sauripterus
finned tetrapod
Barameda
finned tetrapod
Tiktaalik
finned tetrapod
Formation and growth of these bones is
regulated by gene expression during
development. Changes in the regulation
result in evolutionary changes in the adult.
In earliest development, the precursors of
the bones are similar in tetrapods and their
closest relatives.
Eusthenopteron
finned tetrapod
Gogonasus
finned tetrapod
Sterropterygion
finned tetrapod
Rhizodopsis
finned tetrapod
Developmental biology (ontogeny) is an
important aid to paleontologists for
identifying or confirming homologies in
radically transformed groups
Acanthostega
limbed tetrapod
Tulerpeton
limbed tetrapod
Greererpeton
limbed tetrapod
Westlothiana
limbed tetrapod
Coates, M. I., M. Ruta, and M. Friedman. 2008. Ever since Owen: changing perspectives on the early
evolutio of tetrapods. Annual Review of Ecology, Evolution, and Systematics, 39: 571-592.
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Skeletal transformations in early tetrapods
Lobe-fin bones include
humerus, radius and ulna.
These are transformed
into weight bearing limbs.
Hyomandibula attaches
hyoid arch (the support
skeleton between jaws
and gill arches) to
neurocranium.
Transformed into massive
stapes at otic region of
braincase.
Coates, M. I., M. Ruta, and M. Friedman. 2008. Ever since Owen: changing perspectives on the early
evolutio of tetrapods. Annual Review of Ecology, Evolution, and Systematics, 39: 571-592.
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Challenges for a fish out of water
Respiration. Fine structure of gills collapse in air, reducing surface area and
inhibiting gas exchange. Solution: cutaneous respiration, lung respiration.
Support against gravity. Original vertebrate skeleton not really evolved for
supporting the body off the ground. Solution: derived limbs and vertebral column.
Sensory perception. Ever see a fish with ears? Solution: transformation of
hyomandibula to stapes, reorganization of skull for lateral sight, improvements to
olfactory system.
Reproduction 1. Fish typically spawn. Solution: internal fertilization.
Reproduction 2. Egg desiccation. Solution: amniotic membrane
surrounding embryo in egg to prevent desiccation.
Communication. Ever hear a fish scream?
Solution: vocalizations in conjunction with hearing, new
olfactory chemical signals, new visual signals.
Food. Fish are typically predatory and have prey capture strategies
that often involve sucking prey into mouth with water.
Solution: reorganization of jaws, neck, new dietary types.
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Phylogeny of
basal tetrapods
Coates, M. I., M. Ruta, and M. Friedman. 2008. Ever since Owen: changing perspectives on the early
evolutio of tetrapods. Annual Review of Ecology, Evolution, and Systematics, 39: 571-592.
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Structure of the tetrapod middle ear
Inner ear housed in prootic and
opisthotic bones of braincase
Hyomandibula transformed into
stapes, which connects opening in
wall of braincase to tympanum in skin
Laurin, 2010. How Vertebrates Left the Water.
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Early vertebral development
Vertebrae are modeled around notochord from
somite tissue
Neural
tube
Heart
9 day mouse
embryo, before
skeletal
development
begins
Each vertebra develops between somites,
Somites
receiving tissue from one in front and one behind
Directly related to evolutionary transformations in
vertebrae of early tetrapods
Early development of the centrum in the chick (from
Patten, 1958. Foundations of Embryology.)
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Anterior
Vertebral evolution in early tetrapods
Lissamphibians retain intercentrum,
amniotes retain pleurocentrum
Mastodontosaurus
Neural arch
Amniote
Intercentrum
Eryops
Pleurocentrum
Seymouria
Icthyostega
Department of Geological Sciences | Indiana University
(tree from Coates, et al. 2008. Annual Review of
Ecology, Evolution, and Systematics, 39: 571-592)
(c) 2011, P. David Polly
G404 Geobiology
Temnospondyls
Close relatives to crown-group
Amphibians
Long-lived group, Early Carboniferous
(ca. 330 mya) to Early Cretaceous
(ca. 120 mya)
Origin of crown-group amphibia
associated with stereospondyls
Possess stereospondylous form of
vertebrae, with the body composed of
the intercentrum like in living
amphibians
Stayton, C.R. and M. Ruta. 2006. Palaeontology, 49: 307-337.
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Amniota and skull fenestrae
Living Mammals
Names of fenestrae:
Temporal fenestra
Supratemporal fenestra
Infratemporal fenestra
Antorbital fenestra
Mandibular fenestration
Turtles
Living Lizards
and Snakes
Living Crocodiles
and Alligators
Lizard-hipped
dinosaurs
Living Birds
Bird-hipped
dinosaurs
Crurotarsi
Aves
Ornithischian
Saurischian
Dinosauria
Lepidosauria
Archosauria
Diapsida
Synapsida
Reptilia
Amniota
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Non-amniote tetrapod skull: Proterogyrinus
from Carroll, 2009. The Rise of Amphibians
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Amniote Skull: Early Anapsid Reptile
(from Romer, 1966, Vertebrate Paleontology)
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Cladogram of selected amniotes
and outgroups
Edmontosaurus
Archaeopteryx
Aves
Dinosauria
Kuhneosaurus
Archosauria
Lepidosauria
Titanophoneus
Dimetrodon
Outgroups to Amniota
Diadectes
Node
Youngina
Captorhinus
Diapsida
Synapsida
Protogyrinus
1. Single temporal
fenestra not bounded
by quadratojugal
1. Supratemporal fenestra
2. Infratemporal fenestra
Synapomorphies of Diapsida
Amniota
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Edmontosaurus
Amniota
Archaeopteryx
Kuhneosaurus
Reduction or loss of the posterior bones of
the cranium associated with origin of the
neck: tabular, postparietal, supratemporal,
infratemporal.
Titanophoneus
Dimetrodon
Diadectes
Youngina
Captorhinus
Protogyrinus
Amniota
Non-amniotes
Outgroup state: large tabular,
postparietal, supratemporal,
infratemporal
Department of Geological Sciences | Indiana University
Amniotes
Ingroup state: small or absent
tabular, postparietal, supratemporal,
infratemporal, often positioned on
posterior of cranium
(c) 2011, P. David Polly
G404 Geobiology
Edmontosaurus
Synapsida
Kuhneosaurus
Opening of the synapsid fenestra between
the jugal, squamosal and post-orbital bones,
not bounded by quadratojugal. (Note is in a
different place than in diapsids).
Surangular, articular, and quadratojugal
reduced in size.
Non-synapsids
Outgroup state: No opening exclusively
between squamosal, jugal, and
postorbital. Surangular and
quadratojugal major parts of skull.
Department of Geological Sciences | Indiana University
Archaeopteryx
Titanophoneus
Diadectes
Dimetrodon
Youngina
Captorhinus
Synapsida
Protogyrinus
Synapsids
Ingroup state: Opening between
postorbital, squamosal and jugal.
Quadratojugal and surangular
reduced and moved posteriorly.
(c) 2011, P. David Polly
G404 Geobiology
Synapsid Amniote
Single temporal fenestra bounded by postorbital,
jugal, and squamosal
(from Romer, 1966, Vertebrate Paleontology)
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Synapsid Amniote
(from Romer, 1966, Vertebrate Paleontology)
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Synapsids - dominant land vertebrates of the Permian
“Pelycosaurs”
Edaphosaurus
Gauthier, Kluge, and Rowe, 1988. Amniote phylogeny.
Department of Geological Sciences | Indiana University
Romer, 1966, Vertebrate Paleontology
(c) 2011, P. David Polly
G404 Geobiology
Derived synapsids
Romer, 1966, Vertbrate Paleontology.
Gauthier, Kluge, and Rowe, 1988. Amniote phylogeny.
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Transformations of the middle ear in synapsids
Quadrate and articular
become smaller as
muscular focus shifts
anteriorly to dentary
Quadrate and articular join
the stapes (formerly
hyomandibula) as small
bones in the middle ear
Angular bone holds
tympanum, becomes
tympanic annulus
Hopson, in Wake et al., Hyman’s Comparative Anatomy.
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Edmontosaurus
Diapsida
Archaeopteryx
Kuhneosaurus
Opening of temporal fenestra between jugal,
quadratojugal, and squamosal (postorbital
sometimes involved).
Titanophoneus
Opening of second fenestra between
parietal, postfrontal, and squamosal
(postorbital sometimes involved).
Dimetrodon
Diadectes
Youngina
Captorhinus
Diapsida
Protogyrinus
Non-diapsids
Diapsids
Outgroup state: No fenestrae
in diapsid positions.
Department of Geological Sciences | Indiana University
Ingroup state: two temporal
fenestrae, one between jugal,
quadratojugal and squamosal, one
between parietal, postfrontal and
squamosal.
(c) 2011, P. David Polly
G404 Geobiology
Early Diapsid Amniote
Double temporal fenestra: top bounded by
parietal, postfrontal, postorbital, and squamosal;
bottom bounded by postorbital, jugal,
quadratojugal, and squamosal (postorbital
sometimes inserts between, as in this skull)
(from Romer, 1966, Vertebrate Paleontology)
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Lepidosaur Diapsid
Loss of quadratojugal opens lower
temporal fenestra on inferior side
(allows for more mobility in lower
jaw)
(from Romer, 1966, Vertebrate Paleontology)
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Ornithischian Dinosaurs
(from Romer, 1966, Vertebrate Paleontology)
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Avian Theropod Dinosaur
(from Romer, 1966, Vertebrate Paleontology)
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Pangea
the Late Permian
(260 mya)
Single continent
Massive global extinction
Reconstruction by Ron Blakey
http://jan.ucc.nau.edu/~rcb7/index.html
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Permo-Triassic extinction
Tetrapod diversity
83%
ca. 251 million years ago
Nearly 95% of the Earth’s species became extinct.
Eruption of Siberian traps peaked 251 mya, covering at least 1.6 million
square km, an area the size of Europe, with 400 to 3000 m of flood
basalt, lasting 600,000 years.
Oxygen isotope data suggest rapid global rise in temperature of 6C, which
combined with Pangea continent configuration, reduces ocean circulation
and dissolved oxygen to create anoxic conditions on the floor.
Bernard et al, 2010. Acta Palaeontologica Polonica, 55: 229-239
Carbon isotope excursions indicate that CO2 increased in atmosphere
through production by the Siberian Traps, which raised global temperature
enough to melt gas hydrate deposits, which further increased
atmospheric CO2 and temperature... “runaway greenhouse effect”.
Tetrapods hard hit, with the dicyondont Lystrosaurus being one of the few
found in fossil record for millions of years after extinction. Forest
communities absent until Middle Triassic.
Marine diversity
47%
60% 57%
82% 53%
Siberian traps - basalt formations left by surficial lava flow
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly
G404 Geobiology
Scientific papers for further reading
Benton, M.J. and R.J. Twitchett. 2003. How to kill (almost) all life: the endPermian extinction event. Trends in Ecology and Evolution, 18: 358-365.
Coates, M. I., M. Ruta, and M. Friedman. 2008. Ever since Owen: changing
perspectives on the early evolution of tetrapods. Annual Review of Ecology,
Evolution, and Systematics, 39: 571-592.
Smith, R.M.H. and P.D. Ward. 2001. Pattern of vertebrate extinctions across
an event bed at the Permian-Triassic boundary in the Karoo Basin of South
Africa. Geology, 29: 1147-1150.
Stayton, C.R. and M. Ruta. 2006. Geometric morphometrics of the skull roof
of stereospondyls (Amphibia: Temnospondyli). Palaeontology, 49: 307-337.
Department of Geological Sciences | Indiana University
(c) 2011, P. David Polly