Fossils are clues to the type of organisms that roamed or swam on the
Earth. However, fossils provide us with more information. They can tell
us about the paleoecology or the relationship between organisms
and their environments, if we can decipher the clues. Paleontologists
want to determine the physical, chemical and biological interactions
that can limit the distribution and abundance of different species. They
are always searching as to why an organism may have gone extinct. Today
we know that when an organismís environment changes or when other
organisms invade another habit, extinction can occur.
Fossils also indicate that organisms have changed through time. As we
learn which fossils lived in what time, we can retrace how the
environment looked and assign periods of time to each fossil group.
Horseshoe crabs for instance have not changed since they were first
recorded in the fossil record. Foraminifera a protist, changes
shapes through time and help geologist age date rocks.