Question

cambrian web quest
when was the cambrian period?
about 3.6 million years ago
about 220 million years ago
about 550 million years ago
about 50 million years ago

Explanation:

The Cambrian Period is a significant geological time - frame. Through geological research and dating methods, it is known that the Cambrian Period occurred approximately 550 million years ago.

Answer:

about 550 million years ago