Lifeforms have changed throughout Earth's geologic history. Scientists learn about these changes by studying the fossil record. For example, scientists have learned when different groups of organisms first appeared. These events can be placed within specific periods on the geologic time scale, which is shown below.


Fishes with jaws first appeared during the Silurian period, and dinosaurs first appeared during the Triassic period. Large mammals first appeared after both dinosaurs and fishes with jaws.

Using this information and the geologic time scale above, choose the period in which large mammals first appeared.
A.
Permian
B.
Ordovician
C.
Tertiary
D.
Cambrian