The Phanerozoic eon began at the same time as which of these? Select all that apply.
A. the start of the Paleozoic era
B. the start of the Cambrian period
C. the end of the Proterozoic eon
D. the start of the Precambrian super-eon
The Phanerozoic Eon is a period of geological history that spans 542 million years and is typically subdivided into three eras. These eras are: Paleozoic Era: 542 to 251 million years ago. Mesozoic Era: 251 to 65 million years ago.
