THE DIFFERENT TYPES OF FOSSILS

THE DIFFERENT TYPES OF FOSSILS

depend on the fossilization process

ORIGINAL remains

remains of perfectly preserved organisms

example:

dinosaur bones

CASTS

imprint left in the rock by the hard parts of the organism that dissolve

REPLACED remains

the organic substance is replaced by minerals

example: pyritized ammonite

pyrite has replaced the substances of which the shell was made

TRACE FOSSILS

they were not formed from the organism’s body

example:

they can be

footprints

shells

nests

LIVING FOSSILS

animals and plants are called this

that

have remained unchanged for millions of years