Fossil Lab
Fossils are the evidences of living organisms that have been preserved in sedimentary
rock. They may be the mineralized remains of the organism or parts of the organism, or
artifacts made by the organism, such as foot prints or full body prints. For the following
fossil samples, be able to identify the fossil by name and tell the information cited.
Crinoids
These were relatives of starfish, living on the floors of shallow
seas. Fossil remains resemble rolls of Life-Savers candy,
usually with a 5-pointed hole. The animal consisted of a
holdfast, or pedestal that was attached to the ocean floor, with a
slender stem growing upward. At the top of the stem there was a
“head” that resembled a modern starfish. The center of this head
looks like a 5-sided acorn.
In these samples you will see stem sections, loose stem circles,
heads, holdfasts (large spheres), and whole specimens (display
case #5, bottom shelf).
Petrified Wood
This is what remains when all of the wood molecules in a chunk of ancient wood are
replaced by mineral crystals. The result is a precise copy of the original chunk, only in
stone. Often, you can see the prints of the grain and wood fibers clearly.
Bryozoans
These were colonial animals, meaning that they lived as a cluster. They secreted a
calcium-based pedestal to live on, similar to corals. The fossils seen here are the
pedestals.
Trilobites
Trilobites are a common, and popular fossil for collectors. All trilobite species are
extinct. The closest living relative of trilobites is the horseshoe crab. For whole
specimens, see display case #2 and #5.
Ammonites
Although this shell fossil looks like a snail shell, it actually belonged to an animal that
was more like an octopus. Similar to modern nautiluses, ammonites floated upright with
their tentacles extended from the shell.
Brachiopods
These animals were similar to modern clams and oysters except that they are symmetrical
from side to side rather than top to bottom. Brachiopods were sessile, meaning that they
spent their life attached to something. There are a few species of living brachiopods, but
the ones seen here are all extinct.
Pelecypods
This is a general term for bivalve, or 2-shell animals, such as clams, oysters, and mussels.
The name mean “axe foot” because of the shape of its soft parts. Compare these to the
brachiopods and note the symmetry difference.
Gastropods
This is a general term for univalve, or 1-shell animals, such as snails. The name means
“stomach foot” since the animal typically stuck its belly out of the shell to move around.
Worm Tubes
These fossils are actually the sediments that hardened inside of empty worm holes in the
sea floor.
Dinosaurs
Most of what remains of this most famous extinct animal group is bones. The reddish
samples are from a Mosasaur. The black samples are from a cat-sized dinosaur called
Captorhinus. Both samples were recovered in Oklahoma. Also, look at the joint-bone in
display case #1 outside of lab.
Captorhinus
Mosasaur
We tend to focus on the large dinosaurs like T. Rex, when most species that we know
were small like Captorhinus.
Corals
Like the bryozoans, coral animals secreted and formed their own base to sit on. Living
species today form the large reefs that are found in much of the ocean. Reefs provide
habitat for many other types of ocean life. The specimens you see here are extinct forms.
Ferns
These are well-preserved fern leaves in slate rock. They were found associated with a
coal vein in eastern Oklahoma.