Gorgonopsian bone histology_3

The Gorgonopsia were the “sabre-toothed” cats of the Permian; medium-sized to large therapsids equipped with unusually elongated canine teeth that were used to bring down large prey. They were efficient, capable hunters and the dominant predators of the Late Permian terrestrial ecosystem. They form the most basal group of the Theriodontia, a derived group of nonmammalian therapsids, which also include the Therocephalia and Cynodontia (the latter of which includes mammals as a derived subgroup). Despite their success as the dominant predators of the Late Permian, the gorgonopsians did not survive the end-Permian mass extinction; the most catastrophic mass extinction in Earth’s history that occurred approximately 252 million years ago. Hypotheses explaining their extinction during this event include large body size, the extinction of their prey base (mostly large dicynodonts), low population levels and/or speciation rates, high trophic levels and specialist habits. However, their biology remains poorly understood due to the paucity of material and a lack of comprehensive morphological and osteohistological studies in a phylogenetic context. More studies on the taxonomy and osteohistology (bone microstructure) of gorgonopsians are crucial for gaining a broader understanding of this group’s evolution and thus possible reasons for their extinction during the end-Permian extinction.