Fossils

What is a replaced bones/teeth/shells fossil?

-Hard parts -These are made of durable material that is preserved in rock

When did the first fungi appear?

1.5-1 BYA

WHen did the first eukarya plankton (protists) appear?

2.5 BYA

WHen did archaea and bacteria appear?

3.7 BYA

When was the cambrian explosion?

530 MYA

What are the three special conditions required for fossilization?

Anoxic (oxygen-poor) environment Rapid burial Presence of hard parts

What are the 6 kinds of fossils?

Body fossils Replaced bones/teeth/shells Molds and casts Carbonized impressions Permineralization Trace fossils

Next?

Bones become rock- like (fossilize)

What is the next step?

Bones/prints are covered by sediments

What type of fossil will be found in a high-energy environment?

Broken fossil fragments

What type of fossil is formed from soft or semi-soft organisms being pressed flat between layers of sediment?

Carbonized impressions

What is the first step in forming a fossil?

Creature dies, leaving behind body and or footprint

What happens to fossils when they go through metamorphism?

Destroyed by pressure and temperature

What is the second step in forming a fossil?

Flesh rots away, bones and prints will remain

What is a trace fossil?

Formed from marks left in or on sediments -footsprints -burrows -feeding traces

What is the next step?

Sediment lithifies

Most fossils are found in what type of rock?

Sedimentary

What type of fossils can be seen with the naked eye?

Macrofossils

What type of fossils can only be seen with an electron microscope?

Microfossils

Next step?

Minerals in the ground water replace the bones

What is a permineralization fossil?

Minerals precipitate out of groundwater and fill holes in porous material

What is a cast fossil?

Mold that is filled by sediment that is lithified will create a cast.

Are fossils found in intrusive igneous rocks?

No

Why are most fossils found in sedimentary rock?

Organisms die and are usually buried by sediments, or organisms will travel through or sediments leaving and imprint

What type of organisms commonly make microfossils?

PLankton Pollen Algae Bacteria

Which type of environment will result in good fossil specimens?

Quiet water

What is a mold fossil?

The hole left behind in rock when the shell is dissolved away, calcite shells dissolve easily.

Final step?

Uplift and erosion exposes the fossil

What is a body fossil?

Whole body preserved -Wooly mammoth body from permafrost - Insects in amber or tar

Can fossils occur in volcaniclasts?

Yes