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Gordodon kraineri is a new genus and species of edaphosaurid eupelycosaur known from an associated skull, lower jaw and incomplete postcranium found in the early Permian Bursum Formation of Otero County, New Mexico, USA. It has a specialized dental apparatus consisting of large, chisel-like incisors in the front of the jaws separated by a long diastema from relatively short rows of peg-like maxillary and dentary cheek teeth. The dorsal vertebrae of Gordodon have long neural spines that bear numerous, randomly arranged, small, thorn-like tubercles. The tubercles on long neural spines place Gordodon in the Edaphosauridae, and the dental apparatus and distinctive tubercles on the neural spines distinguish it from the other edaphosaurid genera-Edaphosaurus, Glaucosaurus, Lupeosaurus and Ianthasaurus. Gordodon is the oldest known tetrapod herbivore with a dentary diastema, extending the temporal range of that anatomical feature back 95 million years from the Late Triassic. The dental apparatus of Gordodon indicates significantly different modes of ingestion and intraoral transport of vegetable matter than took place in Edaphosaurus and thus represents a marked increase in disparity among edaphosaurids. There were two very early pathways to tetrapod herbivory in edaphosaurid evolution, one toward generalized browsing on high-fiber plant items (Edaphosaurus) and the other (Gordodon) toward more specialized browsing, at least some of it likely on higher nutrient, low fiber plant items. Gordodon shows a surprisingly early specialization of the dental apparatus and indicates how incomplete our knowledge is of edaphosaurid evolution, disparity and diversity.

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A small number of enigmatic vermiform fossils from the Upper Pennsylvanian (Virgilian) Kinney Quarry Lagerstätte in the Manzanita Mountains of central New Mexico have previously been documented. We add here an additional example to this record. The specimen (NMMNH P57873) is preserved as a part and counterpart on laminated calcareous shale from Kinney unit 3. Unit 3 contains a mixture of terrestrial and aquatic faunas. The specimen consists of an elongate fossil that is at least 60 mm long. It is likely preserved in dorsolateral aspect. There are approximately 40 regularly alternating dark and light transverse bands on the long axis. The dark areas are covered by a thin carbonized layer showing fine striations. The bands are about 1 mm wide and 3 mm long. There were likely more of these but the preservation is indistinct toward the presumed posterior. The other end of the specimen is relatively well preserved and we interpret this as the anterior. It shows three appendages extending from a relatively thick, light colored band. There is no indication of a separate head. The appendages resemble an onychophoran oral papilla and antennae. There are at least 26 irregularly spaced, cone-shaped appendages along the likely ventrolateral margin. These leg-like structures are about 2 mm long and about 1 mm at their base. They have no indications of claws, setae or aciculae. There were probably more along the length but the preservation is indistinct towards the posterior. The opposite margin, which we interpret as dorso-lateral, appears somewhat irregular. Several cone-shaped appendages can be seen along the posterior end, which may indicate that the specimen was rotated into a dorsoventral orientation along this portion. P-57873, despite the carbonized surface, lacks any recognizable structures that indicate it is a plant. It is more likely a segmented, soft-bodied animal. The conspicuous leg-like structures could be lobopodia or parapodia, which would indicate a possible polychaete or onychophoran identity. The overall morphology of the body is more indicative of an onychophoran.