Catastrophic disruption of ecosystems in the late Permian period resulted in the greatest loss of biodiversity in Earth’s history, the Permian-Triassic mass extinction event (PTME). The fossil record from that period reveals drama and turmoil as species struggled to become established in their changing environment. An example of this unstable species is a saber-toothed tiger-sized creature called Inostrancevia.

According to a new fossil discovery, Inostrancevia migrated 7,000 miles across the supercontinent of Pangea, filling a gap in a distant ecosystem that had lost its apex predators before it went extinct.

Before this discovery, this saber-toothed creature had only been found in Russia. However, Christian Kammerer discovered the remains of two sizable predatory species not commonly found in the area at the Field Museum in Chicago while studying the fossil record of South Africa’s Karoo Basin.

According to Pia Viglietti, a research scientist at the Field Museum in Chicago, the fossils themselves were highly unexpected. It is still being determined how they got to South Africa from Russia or how long it took them to cross Pangea. But the fossils’ uniqueness wasn’t just due to their remote location.

The arrival of Inostrancevia from 7,000 miles away and subsequent extinction indicates that these apex predators were “canaries in the coal mine” for the larger extinction event.

The ancient animal had the appearance of an “apex predator.” Inostrancevia was a gorgonopsian, a group of proto-mammals that included the first saber-toothed predators on the planet. Although it had skin similar to an elephant or a rhinoceros, it was about the size of a tiger. It belonged to the same animal family as today’s mammals, despite having a somewhat reptilian appearance.

Viglietti said, “When we looked at the ranges and ages of the other apex predators normally found in the area, the ridgeline gorgonopsians, with these Inostrancevia fossils, we found something really exciting. The local carnivores were dying out long before even the great extinction we saw in the Seeing karoo, is extinct – by the time the extinction starts in other animals, they are gone.

Co-author Jennifer Botha, Director of GENUS Center of Excellence in Paleosciences and Professor at the Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, said: “This demonstrates that the South African Karoo Basin continues to produce crucial data for understanding the most catastrophic mass extinction event in Earth’s history.”

Christian Kammerer, the study’s first author and a research curator of paleontology at the North Carolina Museum of Natural Sciences and research associate at the Field Museum, said: “We have shown that the shift in which groups of animals assumed the role of apex predators occurred four times in less than two million years around the Permian-Triassic mass extinction event, which is unprecedented in the history of life on land. This underscores the extreme of this crisis, with even fundamental roles in ecosystems that are in extreme flux.”

The vulnerability of these apex predators is consistent with what we see today. “Apex predators in modern environments tend to be at high risk of extinction and are usually among the first species to be locally extirpated due to human-induced activities such as hunting or habitat destruction,” Kammer says. “Think of wolves in Europe or tigers in Asia, species that reproduce and grow slowly and need large geographic areas to roam and hunt prey, which are now absent from most of their historical ranges. We would expect that ancient apex predators would have had similar vulnerabilities and would be among the species first to go extinct during mass extinction events.”

“As well as shedding new light on the extinction event that contributed to the rise of the dinosaurs. The study is important for what it can teach us about the ecological disasters the planet is currently experiencing.”

Magazine reference:

  1. Christian F. Kammerer, Rapid Turnover of Apex Predators in African Terrestrial Fauna Around the Permian-Triassic Mass Extinction, Current Biology (2023). DOI: 10.1016/j.cub.2023.04.007