The Phanerozoic Eon,with its widespread shelly fossils similar to groups of marine organisms living today,began in
A) 1.8 Ga.
B) 541 Ma.
C) 750 Ma.
D) 65 Ma.

Question

Quizplus · Accepted Answer

The Phanerozoic Eon began 541 million years ago (Ma). This is significant because it marks the beginning of a rich diversity of shelly fossils similar to modern marine organisms. The other options are not correct as they represent different time periods, such as 1.8 billion years ago (Ga) which is part of the Proterozoic Eon, and 65 million years ago (Ma) which is the end of the Cenozoic Era.

The Phanerozoic Eon,with Its Widespread Shelly Fossils Similar to Groups