What are three characteristics of a good index fossil?
The ideal index fossils are those that are abundant, easy to identify, short-lived, widely distributed, and occur in many types of rocks. Abundance is important because fossils must be easy to find in the rock layer. Identifying the fossils is simpler if their shapes and features are distinctive. Ideally, the fossils should be identifiable where they are found and not require any special preparation in a laboratory.
