Dimetrodon

We call a Dimetrodon a "fin-bacl"for obvious reasons. The tops of the vertebrae grew up into tall rods of bone, held togeteher in life by a sheet of tough skin. Some scientists have hypothesized that the Dimetrodon fin may have been a solar panel. In the cool morning, the fin-back could turn sideways to the sun and let the rays heat up its body. If Dimetrodon got over-heated at noon, it could turn its fin again so the breeze went over the fin surface.