Question #431a6
1 Answer
Jun 23, 2016
Index fossils are fossils of common and widely distributed species that can be used to date unknown fossils.
Explanation:
Index fossils are very useful in paleontology. These fossils are fossils of commonly found creatures that were widely distributed but unique to a specific time period.
For example, ammonites are index fossils. They were found in many places during the Mesozoic Era (245 - 65 million years ago) but went extinct in the K-T extinction event 65 million years ago. Therefore, if a fossil sample has ammonite fossils in it, it can be reasonably assumed that any other unknown fossils in the same sample came from the same era as the index fossils.
