Fossil Identification Chart
NAME
AGE
NOTES
1
Fossil Fern
Mississippian –
Pennsylvanian
The imprints and carbonized remains of fern fossils are abundant due to the
slow decay rates found in swamps. Such swamps were widespread around
the world during this time in the Earth’s history.
2
Petrified Wood
Lower Cenozoic
In order for wood to be fossilized after a tree has died, burial needs to occur fast
enough so that the tree’s soft tissue is not destroyed by insects, mold or fire.
3
Lamp Shell
Paleozoic
Lamp shells, or brachiopods, are animals that live in the ocean. They are
referred to as “lamp” shells due to their shape, which resembles old-fashioned
gas lamps.
4
Lamp Shell
Paleozoic
Lamp shells, or brachiopods, are very abundant in Paleozoic oceanic rocks.
Rhynchonellid refers to the family taxonomic name of this brachiopod.
Eocene
The hard shell of these freshwater snails has been replaced by silica to form
agate. The shell is usually the only part of the animal that has a chance to be
preserved as a fossil. Elimia is the true taxonomic name.
(Atrypid)
(Rhynchonellid)
5
Snails
6
Cast of Snail
7
Crinoid Stem
Paleozoic
Crinoids, or sea lilies, are animals distantly related to starfish. They are
called sea lilies based on their plant-like behavior of living in one spot on
the ocean’s floor and having “arms” that radiate out like a flower.
8
Shark or Fish
Vertebra
Cretaceous to
Lower Cenozoic
A vertebra (plural vertebrae) is a bone that forms part of some animal’s back.
Most vertebrate fossils are found as single bones due to the decay of soft
tissue that connects vertebrae and other bones together.
9
(Sting) Ray Tooth
Cretaceous to
Lower Cenozoic
Rays are vertebrates distantly related to sharks. A ray’s tooth is flat in
order to crush the shells of clams and other animals.
10
Shark’s Tooth
Cretaceous to
Lower Cenozoic
While most vertebrate fossils are rare, the hard teeth of sharks are very
common due to a single shark shedding over 10,000 teeth in a lifetime.
(“Turritella” Agate)
A cast is a filled-in cavity. The hollow shell of the snail became filled with
sediment that later hardened into rock, but the original shell was not
preserved.
KEY TERMS
Fossil: The remains of a once living creature. Usually the chemical composition of these remains has changed,
allowing for the fossil to be preserved in rock.
Preservation: The way, “geologic process,” that the remains of a dead creature are turned into a fossil (“fossilized”).
Age (Geologic Time): Geologists have given formal names to past periods of time in the Earth’s history
(for example, “Cretaceous” refers to rocks and fossils that are about 145 to 65 million years old).
Taxonomic Name: A formal name that scientists use to identify an individual type or related group of living creatures.