Question 1
By the late ________ period, true air-breathing amphibians with fish-like heads and tails had evolved.
◦ Silurian
◦ Devonian
◦ Ordovician
◦ Cambrian
Question 2
The ________ period was the "golden age of trilobites."
◦ Ordovician
◦ Devonian
◦ Silurian
◦ Cambrian