Which of the following is an essential characteristic of an index fossil?
A) The fossils are exceptionally abundant and well preserved.
B) The fossils occur in deep- water marine sediments, but the organism actually lived in the sunlit, surface layer of the ocean.
C) The organism only lived for a short period of geologic time.
D) The organism lived only in specific environments such as beaches or estuaries.

Question

Quizplus · Accepted Answer

An essential characteristic of an index fossil is that the organism only lived for a short period of geologic time. This allows for the fossil to be used to date rock layers more accurately. Choices A, B, and D do not necessarily define an index fossil.

Which of the Following Is an Essential Characteristic of an Index