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''Eryops'' meaning "drawn-out face" because most of its skull was in front of its eyes (Greek ερυειν, ''eryein'' = drawn-out + ωψ, ''ops'' = face) is a genus of extinct, amphibious temnospondyls. It contains the single species ''Eryops megacephalus'', the fossils of which are found mainly in early Permian (about 295 million years ago) rocks of Archer County, Texas, but have also been found in late Carboniferous period rocks from New Mexico. Several complete skeletons of ''Eryops'' have been found in lower Permian rocks, but skull bones and teeth are its most common fossils. == Description == ''Eryops'' averaged a little over long and could grow up to , making them among the largest land animals of their time. Adults weighed about . The skull was proportionately large, being broad and flat and reaching lengths of . It had an enormous mouth with many curved teeth. Its teeth had enamel with a folded pattern, leading to its early classification as a "labyrinthodont" ("maze toothed"). The shape and cross section of ''Eryops'' teeth made them exceptionally strong and resistant to stresses.〔 The palate, or roof of the mouth, contained three pairs of backward-curved fangs, and was covered in backward-pointing bony projections which would have been used to trap slippery prey once caught. This, coupled with the wide gape, suggest an inertial method of feeding, in which the animal would grasp its prey and thrust forward, forcing the prey farther back into its mouth.〔Rinehart, L. F., & Lucas, S. G. (2013). Tooth form and function in temnospondyl amphibians: relationship of shape to applied stress. ''New Mexico Museum of Natural History Bulletin'', 61: 533-542.〕 The skeleton of ''Eryops'' was much more strongly built and sturdy than related temnospondyls. The limbs were especially large and strong. The pectoral girdle was highly developed, with a larger size for both increased muscle attachments. Most notably, the shoulder girdle was disconnected from the skull, resulting in improved terrestrial locomotion. The crossopterygian cleithrum was retained as the clavicle, and the interclavicle was well-developed, lying on the underside of the chest. In primitive forms, the two clavicles and the interclavicle could have grown ventrally in such a way as to form a broad chest plate, although such was not the case in ''Eryops''. The upper portion of the girdle had a flat scapular blade, with the glenoid cavity situated below performing as the articulation surface for the humerus, while ventrally there was a large flat coracoid plate turning in toward the midline.〔Pawley, K., & Warren, A. (2006). The appendicular skeleton of ''Eryops megacephalus'' Cope, 1877 (Temnospondyli: Eryopoidea) from the Lower Permian of North America. ''Journal of Paleontology'', 80(3): 561-580.〕 The pelvic girdle also was much larger than the simple plate found in fishes, accommodating more muscles. It extended far dorsally and was joined to the backbone by one or more specialized sacral ribs. The hind legs were somewhat specialized in that they not only supported weight, but also provided propulsion. The dorsal extension of the pelvis was the ''ilium'', while the broad ventral plate was composed of the pubis in front and the ischium behind. The three bones met at a single point in the center of the pelvic triangle, called the ''acetabulum'', providing a surface of articulation for the femur.〔 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.〔Romer, A. S., & Witter, R. V. (1941). The skin of the rachitomous amphibian ''Eryops''. ''American Journal of Science'', 239(11): 822-824.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Eryops」の詳細全文を読む スポンサード リンク
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