Fossils in Precambrian rocks are rare, while there are many fossils in rocks from the Phanerozoic eon. What does this evidence suggest? A. There was a major change in the diversity of life in the Phanerozoic eon, probably due to mass extinction. B. There was no life in the Precambrian eon. C. The rocks from the Phanerozoic eon are much harder than those from the Precambrian eon. D. There was no change in the diversity of life in the Phanerozoic eon.

Question

Ann Mcfarland

Biology

24 July, 10:18

Fossils in Precambrian rocks are rare, while there are many fossils in rocks from the Phanerozoic eon. What does this evidence suggest? A. There was a major change in the diversity of life in the Phanerozoic eon, probably due to mass extinction. B. There was no life in the Precambrian eon. C. The rocks from the Phanerozoic eon are much harder than those from the Precambrian eon. D. There was no change in the diversity of life in the Phanerozoic eon.

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Hugh Dickerson · Answer 1

The Phanerozoic eon is the eon of visible life. It started about 541 million years ago. It represents only 1/8 th of the time since Earth's crust formed. Precambrian eon is older : it extends from 4.6 billion years ago to the Phanerozoic eon. Fossils in the Precambrian eon are rare. In the late Precambrian eon evolved the first multi-cellar organisms.

Answer:

B. There was no life in the Precambrian eon.