Mammals were the dominant form of life in
A) the Cenozoic Era.
B) the Mesozoic Era.
C) the Paleozoic Era.
D) Precambrian time.

Question

Quizplus · Accepted Answer

Mammals first appeared in the late Triassic period of the Mesozoic Era but did not become dominant until the Cenozoic Era, which began approximately 66 million years ago. During the Cenozoic Era, mammals diversified and evolved to fill many ecological niches, including those previously occupied by dinosaurs.

Mammals Were the Dominant Form of Life in