Question

Which of the following best explains the “explosion” of fossils observed during the Cambrian Period?

the first animals to have hard, preservable parts (shells and exoskeletons) evolved during the Cambrian


an extinction event destroyed nearly all fossils that existed at the end of the Vendian Period


a mass migration at the end of the Vendian Period localized species in a more concentrated area


the gradual warming of the climate during the Cambrian Period encouraged the proliferation of species

Answer 1

I believe the answer is A) the first animals to have hard, preservable parts (shells and exoskeletons) evolved during the Cambrian. The Cambrian period is the first geological period of the Paleozoic era. The Cambrian explosion gave rise to the first representatives of modern animal phyla. Fossils from that period include representatives of animal phyla having mineralized shells or skeletons.