Skull larger than in any other known microsaurian, unless Baphetes proves to be microsaurian; cranial elements sculptured with pits and coarse grooves; lacrimal element present, teeth large, curved inwards and fluted; mandible heavy; orbits located far back on the skull and near the median line so that the interorbital space is about half the space from the outer edge of the orbit to the border of the skull, thus approaching the condition known in Eryops; the ribs (?) are strong, heavy, and curved, with an incipient tubercle.
Genus MACRERPETON Moodie, 1909.
Moodie, Jour. Geol., XVII, No. 1, pp. 72-74, fig. 17, 1909.
Type: Macrerpeton huxleyi Cope.
The genus Macrerpeton was proposed for the reception of the amphibian species described by Cope as Tuditanus huxleyi ([123]). This form he placed provisionally in genus Tuditanus, since it seemed to present the same type of sculpturing of the cranial elements similar to that found in T. radiatus Cope. But this species has been removed from Tuditanus and placed in a new genus, Erpetosaurus ([462]). A close study of the type specimen of Tuditanus huxleyi Cope shows ([465]) great variation and distinction from any of the species described from Linton, Ohio, or indeed from any Carboniferous form thus far known.
The specimen represents the left side of the face, and the characters exhibited by the fragment are supported by more complete material (No. 2933, Am. Mus. Nat. Hist.). The skull shows a close approach to the higher labyrinthodonts in its shape. The orbits are far removed from the border of the skull. The arrangement of the bones of the skull resembles that of Capitosaurus from the Keuper of Europe. The jaw is for the most part slender, with a pronounced downward inflection at the coronoidal part. The teeth are heavy and strong and are curved backwards. They have the strong longitudinal fluting which is characteristic of the labyrinthodonts. Another character which is distinctive is the pattern of cranial sculpture. This consists of inosculating pits and grooves of a coarse character and compares favorably with the sculpturing of Triassic labyrinthodonts. If Macrerpeton really represents a labyrinthodont form of Amphibia it is the oldest of the known Labyrinthodontidæ, since it seems probable that the Eosaurus vertebræ came from a higher horizon.
Macrerpeton huxleyi Cope, 1874.
Cope, Trans. Am. Phil. Soc., XV, p. 274, 1874.
Cope, Geol. Surv. Ohio, II, pt. II, p. 397, pl. xxxiv, fig. 2, 1875.
Lesley, Dictionary of Fossils, p. 1237, 1890.