The first of the "Big Five" mass extinctions to clearly have a significant asteroid impact component was at 359 mya, in the middle of the A. Holocene Period B. Hadean Period C. Devonian Period

A mass extinction event occurred about 542 mya that marks the boundary between Precambrian time and the A. Cambrian Period B. Hadean Period C. Permian Period

The ______ era had many extinctions because of large variations in climate.A.PrecambrianB.PaleozoicC.CenozoicD.Mesozoic

(Q012) The Paleozoic Era ended with a mass extinction event that was likely caused byGroup of answer choicesthe formation of Pangaea.intense volcanic activity.the formation of high-latitude ice sheets.the evolution of land plants.

What happened at the end of both the Mesozoic and Paleozoic eras?A.There were major asteroid impacts.B.An ice age occurred.C.A supercontinent broke up.D.There were mass extinctions.

The "First Wave" of Holocene extinction began with disappearance of very large animals by A. overkill (hunting) B. introduction of invasive species C. loss of habitat by global warming