A saber-toothed predator from long before evolution came up with cats
Some 252 million years ago it was a disastrous time to be alive. Erupting supervolcanoes have destabilized ecosystemscausing the planet’s living things to fall into a series of extinctions over the course of a million years, permanently altering life on Earth.
But in what is now southern Africa, some large predators managed to beat the odds for a while. In a published newspaper Monday in the journal Current Biology researchers describe a new saber-toothed beast that appeared unexpectedly and then disappeared, at the very end of the extinction event, challenging the ecological theory that says large predators are the first to fall victim to extinction pressures. The discoveries help unlock some of the extinction dynamics of the Permian-Triassic transition, which could be helpful in better understanding what may have resulted from the ecological crises facing life on our planet today.
Life on land during the Permian period, which lasted from about 298 million to 252 million years ago, was dominated by synapsids, the evolutionary ancestors of mammals or proto-mammals. Dinosaurs were more than a hundred million years away from evolving.
“Permian synapsids include our own ancestors, and not nearly enough people know about them,” said Christian Kammerer, a research curator and paleontologist at the North Carolina Museum of Natural Sciences and an author of the paper. These synapsids, he added, “are more closely related to us than any dinosaur or other reptile.”
Gorgonopsians were a group within the synapsids. These four-legged carnivores hunted with saber-toothed teeth protruding from a square rectangular snout. “They were kind of the T.rex of their day,” said Pia Viglietti, a research scientist at the Field Museum of Natural History and another author of the paper.
Earth’s landmass was then largely a single Pangea supercontinent. The team found that several species of gorgonopsians lived during the approx million years Permian extinction. In almost factory succession, a series of Gorgonopsians evolved, filled that niche, died out, and then was replaced by another.
But what surprised them was the discovery that a gorgonopsian species had evolved and quickly became dominant by the end of the Permian extinction. It closely resembled a Siberian tiger-sized species, Inostrancevia alexandri, which had previously been found only in Russia.
The two new specimens were discovered by Nthaopa Ntheri and John Nyaphuli in 2010 and 2011 during fieldwork led by Jennifer Botha, a co-author from the University of the Witwatersrand. But it wasn’t until the current team re-examined 77 fossils of Gorgonopsians from the Karoo that they realized this was a new species. (Mr. Nyaphuli was responsible for numerous important fossil discoveries, Dr. Viglietti noted, and passed away in 2020.)
They named the animal Inostrancevia africana, suggesting that its ancestors migrated from the far north to the south across the perilous landmass of Pangean. When their descendants dominated what became southern Africa, they had no real competitors because they fed on herds herbivorous Lystrosaurus.
Juan Carlos Cisneros, a paleontologist specializing in the Permian at Brazil’s Federal University of Piauí, who was not involved in the study, said discovering similar Gorgonopsians in both Russia and South Africa was “unexpected and exciting.”
“Apparently, bad luck for southern predators,” he said, referring to the extinction of Gorgonopsian species just before Inostrancevia africana arrived, “ was an opportunity for those from the north.
It wasn’t long before Inostrancevia africana was threatened with extinction. This discovery, the team points out, offers lessons we should heed.
“What killed the gorgonopsians and their whole ecosystem,” said Dr. Viglietti, “was a warming crisis spanning hundreds of thousands of years.” She noted that in today’s world “we see the same changes over the course of a single human lifetime.”
Dr. Kammerer also sees the discovery as an opportunity to take another look at the Permian-Triassic extinction event, often overlooked in favor of the age of dinosaurs that followed.
“Without this extinction, there’s every indication that primordial mammals would have continued to rule the Earth,” he said, “and the ancestors of dinosaurs might never have had a chance.”