Question

JWhen did abundant fossil evidence first appear in the geologic record?


3 billion years ago


300 million years ago


540 million years ago


5 billion years ago

Answer 1

Abundant fossil evidence first appeared in the geologic record around **540 million years ago**, during the Cambrian Period. This era is known for the "Cambrian Explosion," a rapid diversification of life forms and the appearance of many major groups of animals.