Amphibian August #05 – Eryops

One of the few prehistoric amphibians to be regularly featured in popular media – including that one time Star Trek misrepresented it as a synapsid – Eryops was one of the largest land animals of its time. Living during the Late Carboniferous and Early Permian (300-295 mya) of the southwestern United States, the largest known specimens reached a whopping 3m in length (9′10″).

Although it was semi-aquatic and probably fed mainly on fish, its particularly stocky build and stiff torso would have made it a poor swimmer. Instead, it may have been more of an ambush hunter similar to modern crocodiles.

It also probably had a basic eardrum, or tympanum, allowing it to hear sounds in air – which was impressive for the time, considering that many of the contemporary early synapsids were functionally deaf. Although this type of hearing system was once thought to be ancestral to all tetrapods, it now seems like it actually evolved completely independently four or five different times in different lineages.