Earth History & Fossils Flashcard

The layer containing trilobites.

A fossil found in many rock layers and spread across large areas.

True.

They help to determine the relative ages of rock layers.

Rock layer C formed before rock layer A.

Fossils are the remains or traces of ancient living organisms preserved in rock.

Trilobites are often used as index fossils to help date rock layers.

Scientists use index fossils to correlate the age of rock layers across different locations.

Relative age refers to the age of a rock layer compared to other layers.

In undisturbed rock layers, the oldest layers are at the bottom and the youngest are at the top.