Question

Which major characteristic defines the Cenozoic era?(1 point)
Responses

All mammals became extinct.
All mammals became extinct.

Dinosaurs became extinct.
Dinosaurs became extinct.

Dinosaurs became dominant.
Dinosaurs became dominant.

Mammals became dominant.

Answer 1

Mammals became dominant.

After the end-Cretaceous mass extinction (about 66 million years ago), dinosaurs (except birds) disappeared and mammals diversified and became the dominant land animals in the Cenozoic.