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

Question

Quizplus · Accepted Answer

An essential characteristic of an index fossil is that it only lived for a short span of geologic time but was very widespread. This allows it to be used as a time marker or indicator of the age of the rock layer in which it is found.

Which of the Following Is an Essential Characteristic of an Index