FOSSILSEarth Science

Grade 8

Animal Dies

Scavengers eat most of the fleshBacteria eats away at the restSediments cover the remainsGroundwater starts to filter through

Rock is deposited into the bones one cell at a time.A fossil is made!

Eat away the flesh

Eats the rest

(groundwater) passes through

Cover the remains

Change to sediments

Replaces the bone cells

Fossil• Once living material or traces of living material that has become preserved in rock

FOSSIL FORMATION

Petrified remains• Minerals fill in the space held by the original substance• Examples: trees, bones, shells

Carbon film• When leaves or soft bodies materials buried• Examples: film of carbon left behind

Mold• Hole left behind when groundwater dissolves a shell or boneCast• When minerals fill

in the mold

Demo

Trace Fossils• Fossils that show how the organism lived• Examples: footprints, tail marks, eggs, nests, burrows

Trace Fossils

Trace Fossils

Borrows

Trace Fossils

Nest of Eggs

Index fossils• Used to show specific units of time• The best index fossils lived for a short period, but were wide spread

Index Fossils

Index Fossils

Video Clip