Diplocaulus, amphibian skull Gallimimus Most estimates of megalodon's size

Most estimates of megalodon's size extrapolate from teeth

Unlike most modern birds Confuciusornis retained clawed fingers on its wings

Most ammonites are homomorph

This giant vertebra is from the Jurassic Age

Diplocaulus, amphibian skull Gallimimus Most estimates of megalodon's sizeDiplocaulus was an early amphibian distinguished by a boomerang shaped head formed by two elongated bones at the back of the skull. This odd shape may have been used as a hydrofoil allowing it to swim against the current. It also would have made it difficult for predators to swallow. Diplocaulus was a tetrapod, an amphibian, a labyrinthodont, a lepospondyl, and a nectridian. Specs: Diplocaulus sp. Late Carboniferous to late Permian (270 m. y. a.).