Question

Base your answer on the cross section

below and on your knowledge of science. The
cross section shows sedimentary rock layers
containing fossils. The rock layers have not
been overturned since they formed. Explain
why the trilobites are considered to be the
oldest fossil in this diagram.

Answer 1

Because they appeared quickly in geological time, and moulted like other arthropods, trilobites serve as excellent index fossils, enabling geologists to date the age of the rocks in which they are found.

Step-by-step explanation:

Answer 2

Step-by-step explanation:

Fossils generally helps in relative dating of rocks.

The Trilobites are considered the oldest in this rock sequence when we apply the principle of superposition of strata.

The principle states that "in an undeformed/undisturbed sequence of rock, the oldest is always at the bottom while the youngest is on top" .

This principle therefore explains why the Trilobites at the base are considered the oldest.