Inostrancevia was a tiger-sized, saber-toothed gorgonopsian that lived on the supercontinent Pangea during the Permian period, approximately 252 million years ago. The new fossil discovery in South Africa suggests that Inostrancevia migrated 11,300 km (7,000 miles) across Pangea, filling a gap in a faraway ecosystem that had lost its top predators, before going extinct itself.
Inostrancevia with its dicynodont prey, scaring off the much smaller African species Cyonosaurus. Image credit: Matt Celeskey.
“All the big top predators in the Late Permian in South Africa went extinct well before the end-Permian mass extinction,” said Dr. Pia Viglietti, a paleontologist at the Field Museum of Natural History and the University of the Witwatersrand.
“We learned that this vacancy in the niche was occupied, for a brief period, by Inostrancevia.”
Inostrancevia was a gorgonopsian, a group of proto-mammals that included the first saber-toothed predators on the planet.
The animal was about the size of a tiger and likely had skin like an elephant or a rhino.
While vaguely reptilian in appearance, it was part of the group of animals that includes modern mammals.
Prior to the new study, Inostrancevia had only ever been found in Eastern Europe.
But while examining the fossil record of South Africa’s Karoo Basin, the authors identified the fossils of two large predatory animals that were different from those normally found in the region.
“The fossils themselves were quite unexpected. It’s not clear how they made it from what’s now Eastern Europe, or how long it took them to cross Pangea and arrive in what’s now South Africa,” Dr. Viglietti said.
“But being far from home was just one element of what made the fossils special.”
“When we reviewed the ranges and ages of the other top predators normally found in the area, the rubidgeine gorgonopsians, with these Inostrancevia fossils, we found something quite exciting.”
“The local carnivores actually went extinct quite a bit before even the main extinction that we see in the Karoo — by the time the extinction begins in other animals, they’re gone.”
The arrival of Inostrancevia from 11,300 km away and its subsequent extinction indicates that these top predators were ‘canaries in the coal mine’ for the larger extinction event to come.
“This shows that the South African Karoo Basin continues to produce critical data for understanding the most catastrophic mass extinction in Earth’s history,” said University of the Witwatersrand’s Professor Jennifer Botha.
“We have shown that the shift in which groups of animals occupied apex predator roles occurred four times over less than two million years around the Permian-Triassic mass extinction, which is unprecedented in the history of life on land,” added Dr. Christian Kammerer, a paleontologist at the North Carolina Museum of Natural Sciences and the Field Museum of Natural History.
“This underlines how extreme this crisis was, with even fundamental roles in ecosystems in extreme flux.”
The vulnerability of these top predators matches what we see today.
“Apex predators in modern environments tend to show high extinction risk, and tend to be among the first species that are locally extirpated due to human-mediated activities such as hunting or habitat destruction,” Dr. Kammerer said.
“Think about wolves in Europe or tigers in Asia, species which tend to be slow to reproduce and grow and require large geographic areas to roam and hunt prey, and which are now absent from most of their historic ranges.”
“We should expect that ancient apex predators would have had similar vulnerabilities, and would be among the species that first go extinct during mass extinction events.”
The study was published online today in the journal Current Biology.
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Christian F. Kammerer et al. Rapid turnover of top predators in African terrestrial faunas around the Permian-Triassic mass extinction. Current Biology, published online May 22, 2023; doi: 10.1016/j.cub.2023.04.007
