-
Fossil
any remains, impression, or trace of a living thing of a former geologic age
Tell us about past environment – can be used to date rocks
-
Porifera
– sponges, spicules w/ distinctive spikes
-
Protezoa
single cell eukanyote
-
-
Cridaria
Corals, jellyfish, have radial symmetry
-
Brachiopoda
lamp shells, left/right symmetry, shells not symm to each other
-
Mollusca
clams, gastropods (slugs,snails) cephalopods
-
Arthropoda
- Insects, crustaceans,
- Trilobites (early cambrian to late permian)
- segmented exoskeleton, bilateral symm.
-
Echindermata
crinoids, sea urchins, sea star - 5 way radial symmetry
-
Cordata
notochord, aka nerve cord, bilateral symmetry
-
Required factors for fossilization
fast complete burial, anaerobic environment
-
Unaltered Remains
encased in amber, bog people (anaerobiv env.), frozen
-
Replacement
original biological tissues are replaced by new mineral
-
Permineralization
(petrified wood) – fluids fx. dissolved quartz may precipitate though wood, filling in voids
-
Carbonization
thin carbon film left behind after compression, can record detailed microstructure
-
Mold & Cast
- internal and external casts- tracks, burrows, tunnels, footprints (trace) fossilized dung
- (copralites)
|
|
