Question

question 12(multiple choice worth 6 points)
(03.01 lc)
what best describes index fossils?
organisms that existed over a limited period
organisms whose age is hard to detect
fossils that are used in radioactive dating
fossils of the most ancient organisms

Explanation:

Index fossils are defined as organisms that existed over a limited period. This characteristic makes them useful for dating rock layers. Organisms whose age is hard to detect would not serve as index fossils. Fossils used in radioactive dating are not specifically index fossils. Fossils of the most ancient organisms also do not fit the definition of index fossils.

Answer:

Organisms that existed over a limited to .