They solve the enigma of the fate of gorgonopsians after the Permian mass extinction

Before the Age of Dinosaurs, the main apex predators that dominated terrestrial ecosystems belonged to a group of animals remotely related to today’s mammals: the gorgonopsians. These iconic apex predators had prominent saber-shaped teeth and were very successful during the end of the Permian, between 260 and 252 million years ago. However, not all gorgonopsians were large predators; they are a very diverse group that includes species of different sizes and with different lifestyles.

“Gorgonopsians are one of the most iconic groups of terrestrial vertebrates in paleontology for several reasons: they belong to the evolutionary lineage that gave rise to mammals and were the main predators before the appearance of dinosaurs,” comments David P. Groenewald, paleontologist at the Miquel Crusafont Catalan Institute of Paleontology (ICP). What they all share, according to the scientific consensus, is that they went extinct 252 million years ago, during the late Permian mass extinction, also known as “The Great Dying.” A mass extinction that wiped out up to 90% of the species that inhabited the Earth at that time.

However, the extinction of gorgonopsians was complex and is still the subject of scientific debate. This is so to the point that some fossil remains found in South Africa could suggest that at least some species of gorgonopsians survived the mass extinction of the late Permian.

To try to solve this enigma of the past, an international team of paleontologists—including Groenewald—has studied in detail the skulls of three gorgonopsians found in the Karoo basin, South Africa.

To solve this mystery, the objective of the paleontologists in this research was to identify the species to which the skulls belonged and evaluate whether these remains had been transported from Permian rocks to younger rocks – from the Triassic – after the mass extinction. which took place at the end of the Permian. In this way, they were able to verify whether these remains really belonged to post-extinction gorgonopsians.

To reach their conclusions, they used novel techniques such as X-ray computerized microtomography produced in a synchrotron. In a simplified way, this technique consists of performing an “x-ray” on the fossils, which allows us to observe the interior of the bones and – in addition – generate three-dimensional models that can be reconstructed. Computed tomography is an increasingly popular technique in paleontology that allows us to understand the biology and evolution of extinct species in much greater detail.

Ultimately, the research team determined that the skulls undoubtedly belonged to gorgonopsians of the genus Cyonosaurus. This genus is one of the most abundant gorgonopsians in the South African fossil record from the late Permian and is characterized by a relatively small body and an elongated snout. Furthermore, none of the skulls showed evidence of having been transported. However, thanks to the study of the geology of the areas of origin and the formation process of these fossils, the researchers determined that these gorgonopsian remains were not after the extinction at the end of the Permian, thus answering the initial question. .

Therefore, everything indicates that no gorgonopsian species survived “The Great Death”, but the extinction of gorgonopsians was a long and complex process, affected by migrations and successions of different species. A long story that is written in the rocks of South Africa and that thanks to the work of paleontologists we can now read.

The author of this text is Javier Castro Terol, who wrote this press release within the framework of the Master of Evolutionary Paleobiology and Fossil Registry at the UAB. It was the best qualified text within the “Communication Strategy in Paleontology” class and in recognition of its good work it was posted on the ICP corporate website once reviewed by David Groenewald, ICP researcher and co-author of the study.

Different views of the 3D model of the BP/1/4593 skull obtained by X-ray microcomputed tomography. (Reproduced from Benoit et al., 2024)

The study is titled “Did gorgonopsians survive the end-Permian ‘Great Dying’? A re-appraisal of three gorgonopsian specimens (Therapsida, Theriodontia) reported from the Triassic Lystrosaurus declivis Assemblage Zone, Karoo Basin, South Africa.” And it has been published in the academic journal Palaeogeography, Palaeoclimatology, Palaeoecology. (Source: Javier Castro Terol / Catalan Institute of Paleontology Miquel Crusafont)