The most important event during the Cambrian period was the A) ...

[Davideckstein7]

The most important event during the Cambrian period was the
 
  A) emergence of the fishes.
  B) ability of organisms to form an outer skeleton.
  C) emergence of the trilobite.
  D) ability of organisms to develop lungs.

Question 2

What spectacular development in organisms marks the beginning of the Paleozoic era?
 
  What will be an ideal response?

[rosiehomeworddo]

Answer to Question 1

Answer: B

Answer to Question 2

Answer: Organisms developed ability to secrete calcium-carbonate and calcium-phosphate for the formation of hard shells and skeletons. Hard shells provided protection from predators and UV radiation, and made organisms better able to be preserved as fossils.

[Davideckstein7]

Thanks for the timely response, appreciate it

[Liddy]

Excellent