The beginning of the_________ era is marked by the appearance of the first life forms with hard parts.
A)Precambrian
B)Paleozoic
C)Cenozoic
D)Mesozoic

Question

Quizplus · Accepted Answer

The appearance of the first life forms with hard parts marks the beginning of the Paleozoic era. The Precambrian era predates the evolution of hard-bodied organisms, while the Cenozoic and Mesozoic eras are both characterized by the dominance of dinosaurs and other reptiles, which evolved after the Paleozoic era.

The Beginning of The_________ Era Is Marked by the Appearance