| All too often books written for a popular audience include animals such as mammoths, mastodons, plesiosaurs, ichthyosaurs, and the sail-backed Dimetrodon. |
| Dimetrodon and its cousins do, indeed, seem to have met their fate at the hands of a huge impact, with a background of massive volcanic eruptions, just like the dinosaurs. Yet there is a niggling worry in all this. |
| The dentition of dimetrodon further substantiates the movement of the jaw in a simple up and down direction. |
| This is the pattern seen in the dorsal fins of fishes, in Dimetrodon and among iguanid lizards. |
| A comparison of the general pattern of the adductor musculature of Captorhinus and dimetrodon reveals an expected similarity. |
| His next stop was the dimetrodon, the progenitor of Mammalia. |
