The beginning of the Phanerozoic is marked by the______ .
A) existence of a modern atmosphere
B) formation of large land masses
C) abundant life forms compared to earlier times
D) evolution of land plants and animals
E) development of hard body parts, such as shells and bones

Question

Quizplus · Accepted Answer

The development of hard body parts, such as shells and bones, is the defining characteristic of the Phanerozoic Eon, which began about 541 million years ago.

The Beginning of the Phanerozoic Is Marked by The______