Title: Fossils
1Fossils
2What is a fossil?
A fossil is the remains or evidence of
prehistoric life.
- Fossils can be as tiny as a seed.
- A fossil can be as huge as a limb bone from a
giant dinosaur. - For animal or plant remains to become a fossil
they must go through a certain process that
preserves them for up to millions of years after
they have died. - Usually it is only the hard parts of plants and
animals that survive this long process.
3How are fossils created?
It is important to know how a fossil is
preserved. It will tell us what happened to the
fossil before it became buried.
- An animal, or organism dies and is quickly
buried. - There must be the presence of some hard parts.
- Unaltered fossils have little or no change in
their structure. - Altered fossils go through a process that changes
them, but leaves behind different kinds of
fossils.
4Different types of fossils?
There are basically two types of fossils.
Body Fossils These are the actual body parts, or
parts of an organism
Trace Fossils Any evidence of the past that is
not a fossil. Good examples would be animal
tracks, casts, molds, coprolites and impressions.
5Original Skeletal Material
A fossil is the remains or evidence of
prehistoric life.
6Casts or Molds
A leaf fossil is an example of an organism that
leaves a print in a rock. The original part is
dissolved away and the space left is filled with
sediment or mineral matter.
7AmberEntombment
- Certain trees with cones, like pine trees,
contain sticky stuff called pitch. - This pitch comes out of the tree and small
insects get caught in it. - When this becomes buried it hardens and turns
into Amber.
8Borings and Burrows
- Certain worms burrow into rocks, wood, shells,
and all types of sediment. - These burrows are frequently preserved in fine
grained rocks.
9Tar Pits
- Insects and animals got caught in the tar and
then became fossils. - La Brea Tar Pits has yielded a really rich
collection of vertebrate.
10Carbonization
-
- When soft bodied animals become squeezed
between layers of sediment - The liquid is forced out of the animal or plant.
- The liquid becomes coal, oil, or gas.
11Coprolites
- Fossil excrement can give us information about
the diet and size of the animal concerned.