Rhinesuchidae

Rhinesuchidae is a clade of temnospondyl amphibians that lived during the Late Permian to Early Triassic periods. The family is known primarily from fragmentary skulls and osteoderms that have been found in the Karoo Basin of South Africa, the Karoo and Lopingian deposits of Russia, and the Triassic strata of England. Members of Rhinesuchidae were generally large, terrestrial to semi‑aquatic predators, measuring between 1.5 and 2.5 meters in length. Their skulls were tall and robust, with a deep snout, large anterior nares, and a series of osteoderms covering the nape and dorsal surfaces. The teeth were conical and recurved, adapted for seizing and holding prey.

Phylogenetically, Rhinesuchidae is positioned within the larger order Temnospondyli and is closely related to the families Mesoherpetidae and Trematosauridae. Analyses of cranial morphology and postcranial characters have placed Rhinesuchidae as a sister clade to Stereospondyli, indicating a complex evolutionary history of large amphibians during the Permian–Triassic transition. The family is often considered paraphyletic, with some taxa now reassigned to other families based on more recent cladistic studies.

The ecological role of Rhinesuchidae is inferred from their body plan and fossil contexts. They likely occupied predator niches in floodplain and marsh ecosystems, hunting fish, arthropods, and smaller amphibians. Isotopic analyses of their bones suggest a preference for humid environments with substantial river systems. Their extinction coincides with the end‑Permian mass extinction event, after which the temnospondyl diversity declined sharply.

Systematic work on Rhinesuchidae began in the early 20th century with the description of Rhinesuchus macdunni by R. A. D. Smith. Subsequent discoveries expanded the family's geographical range and clarified its morphological diversity. Modern techniques such as computed tomography and cladistic matrix coding continue to refine its taxonomy and resolve its phylogenetic positions, providing insights into the evolutionary pathways of early tetrapods.