[Campbell Biology P.585] What key evolutionary changes characterized the Cambrian explosion,... | Practice Question

What key evolutionary changes characterized the Cambrian explosion, distinguishing it from the preceding Ediacaran period?

  • A: Appearance of large, soft-bodied grazers and filter feeders.
  • B: Sudden emergence of many present-day animal phyla with predatory adaptations and defensive features.
  • C: Origin of all animal phyla, including sponges and cnidarians.
  • D: Diversification of prokaryotes on land.

Explanation

The Cambrian explosion was characterized by the sudden appearance and diversification of many present-day animal phyla, accompanied by the evolution of predatory adaptations like claws and defensive features like sharp spines and heavy body armor . This contrasts sharply with the soft-bodied, non-predatory nature of the preceding Ediacaran biota.