page_title: Arisierpeton
section_title: Vertebrae
hierarchical_section_title: Arisierpeton / Description / Vertebrae
caption_attribution_description: English: Arisierpeton simplex dorsal vertebrae
context_page_description: Arisierpeton is an extinct genus of synapsids from the Early Permian Garber Formation of Richards Spur, Oklahoma. It contains a single species, Arisierpeton simplex.
context_section_description: The string of three posterior dorsal vertebrae GAA 00244, were found in the same pocket as the dentigerous elements, but their association with the holotype and other referred specimens is tentative. The vertebrae have the typical cylindrical, spool-shaped centra, with shallow lateral excavations, but the most striking feature of the centra is the presence of flat ventral surfaces between the rounded anterior and posterior articular surface. The centra are solidly fused to the neural arches, which carry well-developed, massive, transverse processes, short zygapophyseal surfaces, and slender, presumably anteroposteriorly short, simple neural spines. The transverse processes are short and stout, and were not fused to the ribs. The size of the transverse processes indicate that these are most likely posterior dorsal vertebrae. A pair of small excavations are present dorsally on the neural arch, between and slightly posterior to the prezygapophyses. There is no evidence of ventral excavation of the centra for intercentra, a common feature of caseid posterior dorsal vertebrae. Thus, the morphology of the centra and neural arches are entirely in agreement with known caseid morphology. They can be assigned with confidence to a small caseid. However, their assignment to Arisierpeton is tentative and based on co-occurrence and size, and there are no recognizable diagnostic features on the centra below the family level.
caption: Vertebrae
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