Two new species of ancient saber-toothed predators discovered
Scientists led by the North Carolina Museum of Natural Sciences have described two new species of saber-toothed prehistoric predators. The fossils are providing new insight into the early evolution of mammals, which was a time when the role of some carnivores drastically changed.
During the Permian Period, millions of years before the earliest dinosaurs, ancestors of today’s mammals called therapsids dominated terrestrial ecosystems. The diverse creatures, referred to as “protomammals,” included tusked herbivores, burrowing insectivores, and saber-toothed predators.
Most remains of Permian therapsids have been found in the Karoo Basin of South Africa. This South African record has provided scientists with invaluable evidence of the evolution of protomammals.
Therapsid fossils from outside of South Africa, however, are also extremely important because they can be used to examine whether events in the protomammal fossil record represent global or strictly regional evolutionary patterns.
Recent expeditions by the Vyatka Paleontological Museum have produced a collection of very well-preserved Permian fossils recovered near the town of Kotelnich in European Russia, including the remains of two previously unknown species of predatory protomammals.
The first of the two new species, Gorynychus masyutinae, was a wolf-sized carnivore and the largest predator in the Kotelnich fauna. The second new species, Nochnitsa geminidens, was a smaller, long-snouted carnivore with needle-like teeth.
The new species from Russia provide the first evidence that the turnover in predators after the mid-Permian extinction was worldwide and not unique to South Africa.
The mid-Permian mass extinction, which came about eight million years before the well-known and devastating end-Permian mass extinction, played a major role in driving protomammal evolution.
In the late Permian ecosystems, the top predators were giant, saber-toothed gorgonopsians, while therocephalians were generally small insectivores. In mid-Permian ecosystems, however, these roles were reversed. The saber-toothed top predator Gorynychus was a therocephalian, and the only gorgonopsians during this time were much smaller animals.
“In between these extinctions, there was a complete flip-flop in what roles these carnivores were playing in their ecosystems – as if bears suddenly became weasel-sized and weasels became bear-sized in their place,” said study co-author Christian Kammerer.
“Kotelnich is one of the most important localities worldwide for finding therapsid fossils – not only because they are amazingly complete and well-preserved there, but also because they provide an all-too-rare window into mammal ancestry in the Northern Hemisphere during the Permian.”
The study is published in the journal PeerJ.
Image Credit: Matt Celeskey