1. Which animal was there the most species of during the Cenozoic?
2. Which animal was there the most species
of during the end of the Devonian (which is at
the top of the Devonian section)?
3. Of the animals on this graph, which
one was the first to exist?
4.Which animal/s are now extinct?
5.Which animals have survived the longest?
Precambrian/Cryptozoic
6. What time period had the most species alive? _

answer

Explanation:

The Cenozoic Era, meaning "new life" is the current and most recent of the three geological eras of the Phanerozoic Eon. The Cretaceous–Paleogene extinction event (also referred to as the K-Pg, or K-T, extinction event) is the boundary between preceding Mesozoic era and the Cenozoic, which extends from 66 million years ago to the present day. Many species, including all non-avian dinosaurs, became extinct, in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor.

The Cenozoic is also known as the Age of Mammals because the terrestrial animals that dominated both hemispheres were mammals – the Eutherians (placentals) in the northern hemisphere and the Metatherians (marsupials, now mainly restricted to Australia) in the southern hemisphere. The extinction of many groups allowed mammals and birds to greatly diversify so that large mammals and birds dominated the Earth. The continents also moved into their current positions during this era.