The beginning of the Phanerozoic marks an important event in animal evolution-the appearance of organisms with_________ .
A)hard parts
B)cells
C)wings
D)vertebrae
E)none of the above

Question

Quizplus · Accepted Answer

The appearance of organisms with hard parts, such as shells, exoskeletons, and bones, marks the beginning of the Phanerozoic eon, which is characterized by a diversification of animal life and the emergence of many new body plans and ecological niches. This event is known as the Cambrian Explosion and marks a major milestone in the evolution of life on Earth.

The Beginning of the Phanerozoic Marks an Important Event in Animal