How do the characteristics of an index fossil is useful to geologists?

Answer 1

Index fossils are fossilized remains of organisms that serve as convenient reference points to geologists because they were very widely distributed during a very short period. This means that, if a geologist is trying to figure out how old a certain segment of rock is, the presence of an index fossil will give him a very good idea to a pretty high level of certainty.

Most index fossils are aquatic, especially mollusks. This is because (a) mollusks had shells, which are easily preserved, and (b) marine organisms generally fossilize easily because they often live on sand and so turn into sedimentary rock, which forms without volcanic activity (like igneous) or intense pressure (like metamorphic).

One good example of an index fossil is Paradoxides, a species of trilobite that was distributed in seas all over the world, but only for a very small amount of time during the Cambrian Period, about 540 million years ago.

Answer 2

Index fossils are the remains of organisms that lived during a very specific and well-defined time span, and are able to be recognized from various, distant locations; hence, they are usually marine invertebrates like trilobites or ammonites. They are able to provide a means of dating fossils found with them or in layers above and below them.

Answer 3

It gives information to scientists about the past. It also provides a reference of time throught rock layers. It can identify and define geological periods of time.

Answer 4

They use Index Fossils to study extinct plants or animals from certian time periods