maxillans

Maxillans is a genus of extinct tetrapods known from fragmentary cranial material recovered from Late Permian deposits dating to roughly 260 million years ago in southern Pangaea. The name derives from the prominent maxillae that characterize the preserved skull elements. The holotype consists of a partial left maxilla, parts of the dentary, and a fragmentary braincase, with a second specimen preserving a nearly complete maxillary arcade.

Maxillans are estimated to have been medium-sized, with skulls about 15–25 cm long and a body length approaching 0.8–1.2 meters. The dentition is conical and densely packed, with relatively small intercuspid teeth suggesting a diet of small vertebrates and invertebrates. The jaw joint and muscle attachment sites indicate strong bite forces and capable lateral slicing. The skull architecture implies a prey-capture strategy that relied on rapid closing and powerful shearing to subdue small prey.

Taxonomic placement has been debated. Some analyses assign Maxillans to early diapsids within a proposed Maxilliformes, while others place them in synapsids, near the lineage leading to mammals. The material is too fragmentary to resolve relationships definitively, making Maxillans a focal point in discussions of early amniote jaw evolution. The distribution appears limited to a single stratigraphic horizon, and the fossil record is sparse, but Maxillans contribute to debates about the diversity of jaw morphologies in the Late Permian and the origins of more complex feeding adaptations.

See also Amniotes, Evolution of the jaw, Permian fauna.