Some of the dominant marine reptiles of the Mesozoic were ...

[stevenposner]

Some of the dominant marine reptiles of the Mesozoic were reptiles whose ancestors had evolved on land, but returned to life in the sea. What physiological evidence supports this interpretation?
 
  What will be an ideal response?

Question 2

What role did the creation of the ozone layer have in the distribution of life forms across the planet and why?
 
  What will be an ideal response?

[LVPMS]

Answer to Question 1

Answer: Structure of the fins (same structure as reptile legs/feet) and the development of lungs to breathe air.

Answer to Question 2

Answer: Prior to the ozone layer, life was confined to the sea. Water could protect early life forms from harmful UV radiation. However, ozone also has the capability of reflecting harmful UV rays, so once the ozone developed, life could leave the ocean and begin to colonize the land.

[stevenposner]

Thanks for the timely response, appreciate it

[momolu]

YES! Correct, THANKS for helping me on my review