Eryops (; from Greek , , 'drawn-out' + , , 'face', because most of its skull was in front of its eyes) is a genus of extinct, amphibious temnospondyls. It contains the type species , the fossils of which are found mainly in early Permian deposits of the Texas Red Beds, and Eryops grandis from New Mexico. Fossils have also been found in late Carboniferous rocks from New Mexico and early Permian deposits of Oklahoma, Utah, the Pittsburgh tri-state region, and Prince Edward Island. Several complete skeletons of Eryops have been found in lower Permian rocks, but skull bones and teeth are its most common fossils.
Description
left|thumb|Life restoration
Eryops averaged a little over long and could grow up to , making them among the largest land animals of their time. Adults have been estimated to weigh between . The skull was large and relatively broad compared to coeval temnospondyls; the skull reached lengths of around . The configuration of the postcrania is similar to that of other temnospondyls, but the relative degree of ossification and overall size of the animal produce some of the sturdiest and most robust postcrania among Paleozoic temnospondyls.
The texture of Eryops skin was revealed by a fossilized "mummy" described in 1941. This mummy specimen showed that the body in life was covered in a pattern of oval bumps.
Discovery and species
thumb|Cast of the skull
Eryops is currently thought to contain two presently valid species. The type species, E. megacephalus, refers to the "large-headed" aspect of the genus. Remains of E. megacephalus have been found in rocks dated to the early Permian period (Sakmarian age, about 295 million years ago) in the southwestern United States. Most of these specimens, including the type material, have little to no locality information other than that they are from the early Permian of Texas, but more definitively placed specimens are recorded for much of the Cisuralian, including the Putnam, Admiral, Belle Plains, and Clyde Formations.
Various other valid temnospondyl taxa were previously placed in the genus. During the mid-20th century, some older fossils were classified as a second species of Eryops, E. avinoffi. This species, known from Carboniferous period fossil found in Pennsylvania, had originally been classified in the genus Glaukerpeton. Beginning in the late 1950s, '<nowiki/>Eryops anatinus<nowiki/>' and '<nowiki/>Eryops latus<nowiki/>' are both junior synonyms of E. megacephalus. '<nowiki/>Eryops<nowiki/>' ferricolus is now recognized as a dissorophid, Parioxys, '<nowiki/>Eryops platypus<nowiki/>' is a junior synonym of the amphibamid Platyrhinops lyelli, and <nowiki/>'Eryops africanus<nowiki/>' and Eryops oweni<nowiki/>' are rhinesuchids. <nowiki/>'Eryops reticulatus<nowiki/>' is regarded as a nomen vanum, New Mexico, Oklahoma, and Prince Edward Island. The primary material of Eryops that has been reported from the Conemaugh Group in West Virginia has also been reidentified as Glaukerpeton, The ecology of Eryops has been extensively debated and remains without consensus due to conflicting signals from different lines of evidence, such as external morphology, biomechanical modeling, and bone histology. Eryops lived in lowland habitats in and around ponds, streams, and rivers, and the arrangement and shape of their teeth suggests that they probably ate mostly large fish and aquatic tetrapods.