ODONTERPETON TRIANGULARE MOODIE, 1909

Holotype: USNM PAL 4465 + 4467, part and counterpart cannel coal blocks containing the anterior portion of a skeleton exposed in dorsal view ( USNM PAL 4465) and ventral view ( USNM PAL 4467) (Figs 1, 2).

Type locality and horizon: Abandoned coal mine operated originally by the Ohio Diamond Coal Company at Linton, Saline Township, Jefferson County, OH, USA (for details, see Hook & Baird, 1986). Local cannel coal is immediately below the Upper Freeport coal of the Allegheny Group. This horizon is dated as Middle Pennsylvanian (Moscovian).

ReƲised diagnosis: Diminutive recumbirostran with the following distinctive combination of characters: 19 maxillary tooth positions; posterior maxillary teeth enlarged; lateral surface of maxilla bearing series of pits; undulating midline sutures between frontals and parietals; nasals small; short forelimbs; and autopodium with three digits and phalangeal count of 2-4-3. Shares the field of palatal teeth with pantylids and gymnarthrids. Shares with Joermungandr Mann et al., 2021 and brachystelechids large parietals. Shares with Joermungandr and at least Diabloroter Mann & Maddin, 2019 among brachystelechids the anterior position of the pineal foramen. Shares with Joermungandr oval, ornamented dermal scales, a short snout and the presence of a single splenial. Differs from Joermungandr in the absence of an anteriorly restricted tooth row, the greater number of teeth in the upper and lower dental arcade, the presence of a tabular, proportionally shorter nasals and the presence of a well-ossified forelimb and pectoral girdle.