Question

The diagram below shows several layers of sediment below the surface and some fossils that can be found in these layers.


The organism at point W is a bony fish. The organism at point X is a dinosaur. The organism at point Y is a trilobite. The organism at point Z is an amphibian. This diagram suggests that
A.
amphibians are common ancestors of dinosaurs and trilobites.
B.
different species were abundant at different times in Earth's history.
C.
dinosaurs became extinct before the evolution of bony fishes.
D.
trilobites are the oldest living creatures on the planet.

Answer 1

B.

The fossils occur in different sediment layers (older layers are deeper), so each species appears in the rock record at different times. This shows different species were abundant at different periods in Earth's history.