Researchers have discovered the fossils of two new species of saber-toothed predators, according to a series of studies published in the journal PeerJ (available here and here).
The remains were discovered by scientists of the Vyatka Paleontological Museum in a place rich in Permian fossils (299-252 million years ago) near the city of Kotelnich in European Russia
The first of two creatures , Gorynychus masyutinae, was a wolf-sized predator that would probably have been the largest predator in its ecosystem. The second, Nochnitsa geminidens meanwhile, was a small, long-beaked carnivore with needle-like teeth
The species are named after two legendary monsters from Russian folklore: the three-headed dragon Zmey Gorynych and the evil nocturnal ghost Nocnitsa .
According to the researchers, the fossils could help expand our understanding of an important period in the evolution of mammals. Both finds belong to a diverse group of "proto-mammals", so-called Therapsiden, from which all live mammals descend. ( Gorynychus belongs to a subgroup known as therocephalia, while Nochnitsa is part of another subgroup called Gorgonopsia.)
Therapsids A group of lunatens, insectivores, and saber-tooth eaters, like the two new species, roamed Earth millions of years before the earliest dinosaurs.
To date, most Permian Therapsids have been found in southern Africa. This makes fossils from this group found outside of this region ̵
The Gorynychus and Nochnitsa fossils illuminate a time between two mass extinctions – known as the Middle Permian (260 mya) and End-Permian (252 mya) mass extinction – when the roles of certain primal carnivores changed dramatically.
In the middle of the Perm, the top predators-like the Gorynychus specimens found in Kotelnich were Therocephalians, while Gorgonopsis, such as Nochnitsa, were much smaller animals .
But in late Perm, the opposite is the case: the upper predators were typically large, saber-toothed Gorgonopsians, while Therocephalians were rather small insectivores.
"Between these extinctions, there was a complete flip-flop in which roles these carnivores played in their ecosystems – as if bears suddenly became weasels – Size and weasels became bearish in their place, "said Christian Kammerer, author of one of the studies of the North Carolina Museum of Natural History.
Kammerer says that the new species provide the first evidence that the role of proto-mammalian predators has changed worldwide after extinction in the middle of the Permian, and not just a localized effect in southern Africa.
"Kotelnich is one of the most important sites for therapsid fossils worldwide – not only because they are remarkably complete and well preserved, but also because they provide a very rare window into mammalian origin in the Northern Hemisphere during the Permian," added Kammerer added.