These images relate to the PALEONTOLOGY LAB.
The central whorl of Archimedes is all that is left after all the lacey
structure broke away. (Fossilization
type = Replacement)
Boring sponge in a clam shell. This is the same shell that is in the
lab. It looks brown because a strong light is behind it, illuminating the
burrow of the sponge.
These are "normal" views of the shell.
Bird bones from La Brea Tar Pits.
(Fossilization type = Original parts)
Ammonite showing its complex suture pattern (close up on right).
Ammonites (a type of cephalopod) were squid-like animals. They lived in
the last chamber of their shell. As they grew in size the shell grew along
with them. Cephalopods were able to seal off the older parts of their
shells by growing walls. These walls (sutures) are often preserved and
play an important role in the classification of the animal.
(Fossilization type = Replacement)
A cephalopod fossil. Note that the sutures (partition between the
chambers) is a fairly simple, flat wall. Compare this suture to that of
the ammonite above. (Fossilization type
= Replacement)
A nicely preserved coprolite. Animal of origin was a fox-like creature.
(Fossilization type = Replacement)
Coquina is a limestone composed almost entirely of shell fragments. It is
a beach deposit. (Fossilization type =
Original parts)
Crinoid Calyx in limestone. Crinoids lived in shallow, warm and clear water during the
Mississippian period. Paleontologists use the concept of faunal assemblage
to determine ecological niches. In this case the crinoids fossils are
always found with shallow water animals like corals, sponges, mussels and
others. So the crinoids must have been shallow water animals - "Guilt
by association" (Fossilization
type = Replacement)
A
very unusual fossil from the beaches near Venice, FL. It is the inner ear
bone of a whale.
(Fossilization type = Replacement)
The trilobite Elrathia kingii is a denizen of the ancient Cambrian seas
that are now found in the deposits of the Wheeler Shale in central Utah.
All trilobites are extinct and were strictly marine animals. Being
arthropods, however, they did shed their exoskeletons as they grew. These
molts could have been preserved as fossil thus biasing the fossil record.
(Fossilization type = Replacement)
This is an example of the fenestrate (lacy) bryozoan.
(Fossilization type = Replacement)
The "teeth" for brachiopods were not for eating, they were hinge
teeth. (Fossilization type =
Replacement)
This flat, black circular mark on the shale is the fossil. It is an
excellent example of a carbon film.
(Fossilization type = Carbon film)
Sponges are soft bodied animals and when they die they are not normally
fossilized. This unusual fossil was the
result of burial of the sponge before it could deteriorate. It is from the
Permian Kaibab Limestone near Flagstaff, AZ.
(Fossilization type = Replacement)
This specimen has fossil leaves. This requires low energies similar to
those found in slow moving bodies of water like deltas or swamps. In quiet
waters the leaves are not abraded or destroyed but are allowed to settle quietly
to the substrate where they are buried and preserved.
(Fossilization type = Carbon film)
Corals are indications of marine conditions that are shallow, warm, clean and
well aerated. When we find fossils in the rock record we can thus
determine with a high degree of certainty that this was the environment of
deposition. (Fossilization type =
Cast)
This chunk of limestone is from near Payson, AZ and shows a variety of marine
invertebrates.
(Fossilization type = Replacement)
Petrified wood is wood that has been "turned to stone". The process takes
place when the wood is buried and groundwater replaces the wood structure with a
mineral, in this case it was silica (quartz) - which is the most common type of
petrified wood.
(Fossilization type = Replacement)
Trilobites were arthropods and had complex eyes. In this close-up photo
you can get a glimpse of the faceted eyes. They are very much like the
eyes of insects like dragon flies and butterflies.
(Fossilization type = Replacement)
This is a plaster cast of a large trilobite from CA.
(Fossilization type = cast) However, this is
not a fossil.
Shark's teeth are very abundant as fossils. It is similar to the abundance
of trilobites in that a shark continuously produced teeth throughout its life.
Old teeth break off or fall out and replaced by newer ones. Each tooth, of
course, is hard and durable. When they fall to the ocean floor they are
easily fossilized. (Fossilization
type = Replacement)
Stromatolites are cyanobacteria. (cyan - is a blue green color) This
stromatolite is about 2.2 billion years old and represents a time in the
geologic past (Precambrian) when there was not much oxygen in our atmosphere.
This plant (and others) changed that.
(Fossilization type = Replacement)
This specimen is a combination of shells and sand - just what you would expect
to find on a beach.
(Fossilization type = Replacement)