Fossils & Evolution

Paleontology

the study of ancient life and its evolution as recorded by fossils

Paleontologist

a scientist who specializes in studying and interpreting fossils

Fossil

remanent or trace of an organism that has been preserved in rock or sediment

What type of rocks are most fossils found in?

sediments & sedimentary rocks

Where are some fossils found?

in ash or tuff

Fossilization

process of forming a fossil

1st stage of Fossilization

organism dies

2nd stage of Fossilization

organism is rapidly buried in calm ANOXIC environment before DECOMPOSED or DESTROYED

3rd stage of Fossilization

hard bodied (bones) organisms are more EASILY preserved than soft bodied (jellyfish) organisms

Only a ___ % of organisms that have ever lived have been fossilized

tiny/small

Frozen Bodies

like mammoths

Dried Bodies

like mummies

Body Fossils

preserved in amber (tree sap) or tar

Preserved or Replaced

bones, teeth, or shells

Meaning of a Preserved Fossil?

durable mineral that has remained

Meaning of a Replaced Fossil?

unstable mineral that recrystallizes

The shape of bone, tooth, or shell ___

remains

Mold

sediment COMPACTS around organism, organism later DESTROYED, leaving shape of organism

Cast

sediment FILLS a mold, PRESERVING organism shape

Carbonized Impressions

flattened mold or soft organisms

Permineralized

mineral from groundwater precipitate in POROUS material of organism (wood or bone)

Trace Fossils

footprints, burrows, coprolites (poop)