Approximately 252 million years in the past, our Earth was gripped by a cataclysmic event of mass extinction so severe it’s now referred to as “the Great Dying.” Vast volcanic eruptions ignited an unparalleled climate shift, leading to the extinction of 90% of all species, thus setting the stage for the era of the dinosaurs.
This catastrophic event, however, was not a sudden occurrence. Instead, the Great Dying stretched over the course of nearly a million years, marking the end of the Permian period with a drawn-out farewell.
During this prolonged extinction event, a tiger-sized, saber-toothed creature named Inostrancevia symbolized the struggle for survival in the face of the Earth’s drastically shifting environments.
The fossil record reveals a recent discovery that this creature embarked on a 7,000-mile migration across the supercontinent Pangaea, establishing its presence in a far-off ecosystem that had lost its apex predators. Yet, despite its monumental journey, Inostrancevia was also eventually doomed to extinction.
“All the big top predators in the late Permian in South Africa went extinct well before the end-Permian mass extinction. We learned that this vacancy in the niche was occupied, for a brief period, by Inostrancevia,” said Pia Viglietti, a research scientist at the Field Museum in Chicago and a co-author of the new study published in Current Biology.
Indeed, Inostrancevia was not an ordinary creature. Viglietti explained: “Inostrancevia was a gorgonopsian, a group of proto-mammals that included the first saber-toothed predators on the planet.”
Resembling a tiger in size, Inostrancevia likely bore skin akin to an elephant or a rhino, and despite its somewhat reptilian appearance, it was actually a part of the lineage leading to modern mammals.
Before this study, fossils of Inostrancevia had only been identified in Russia. However, during the examination of South Africa’s Karoo Basin fossil record, Christian Kammerer, Viglietti’s colleague, identified the fossils of two large predatory animals that were distinct from those typically found in the region.
“The fossils themselves were quite unexpected,” said Viglietti. The mystery of how these creatures traveled from modern-day Russia, across Pangaea, and arrived in what’s now South Africa remains. Yet, their distant journey was just one facet of what made these fossils remarkable.
The discovery brought forth an exciting revelation. “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,” explained Viglietti. “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.”
Thus, the journey of Inostrancevia from 7,000 miles away and its subsequent extinction suggests that these top predators were like the proverbial “canaries in the coal mine” for the more substantial extinction event that was to follow.
“This shows that the South African Karoo Basin continues to produce critical data for understanding the most catastrophic mass extinction in Earth’s history,” explained study co-author Professor Jennifer Botha, director of GENUS Centre of Excellence in Palaeosciences.
This study also discovered that the role of apex predators shifted an unprecedented four times over a span of less than two million years around the Permian-Triassic mass extinction.
“This underlines how extreme this crisis was, with even fundamental roles in ecosystems in an extreme state of flux,” said study lead author Christian Kammerer, a research curator of paleontology at the North Carolina Museum of Natural Sciences and research associate at the Field Museum.
The susceptibility of these top predators mirrors what we observe in our current ecosystems.
“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,” said Kammerer.
He referred to examples like the European wolves or Asian tigers, species that reproduce and grow slowly and require large areas to roam and hunt prey, but are now missing 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 not only throws new light on the extinction event that paved the way for the rise of the dinosaurs, but also imparts valuable lessons about the ecological crises that our planet currently faces.
“It’s always good to get a better understanding of how mass extinction events affect ecosystems, especially because the Permian is basically a parallel on what we’re going through now,” said Viglietti.
She further emphasized the lack of modern analogs to compare with the mass extinction happening today. The Permian-Triassic mass extinction event offers one of the best references of what our planet might endure due to the ongoing climate crisis and extinctions. But unlike the past, “we know what to do and how to stop it from happening.”
This groundbreaking study not only reveals intriguing aspects of prehistoric life but also serves as a timely reminder of the need to preserve our ecosystems and avert the looming ecological disasters threatening our planet today.
The Great Dying, formally known as the Permian-Triassic (P-Tr) extinction event, is the most devastating mass extinction event that our planet has ever experienced. This catastrophic event occurred roughly 252 million years ago, marking the boundary between the Permian and Triassic geological periods, hence its name.
This extinction event wiped out approximately 96% of marine species and 70% of terrestrial vertebrate species. The sheer scale of life lost earned it the moniker “the Great Dying.” It was an extinction event so severe that it took the Earth up to 10 million years to recover its biodiversity levels.
Several theories attempt to explain the cause of this mass extinction. Most scientists agree that a combination of environmental changes likely led to this catastrophe, rather than a single event.
Massive volcanic eruptions in the Siberian Traps released a vast amount of greenhouse gases, such as carbon dioxide and methane, leading to drastic global warming. These eruptions also spewed out sulfur dioxide, which can cause acid rain and further environmental damage.
The increased global temperatures could have led to the depletion of oxygen levels in the oceans, a state known as ocean anoxia. This could have made the oceans inhospitable for many marine species, leading to widespread death.
Some scientists also theorize that warming oceans might have destabilized deposits of methane hydrates (a type of ice that contains a lot of trapped methane) on the seafloor, leading to a massive release of methane, a potent greenhouse gas. This could have caused temperatures to spike even further.
The Great Dying had significant long-term impacts on life on Earth. In the aftermath of the extinction, a group of reptiles known as archosaurs emerged as dominant, leading eventually to the age of dinosaurs in the later Mesozoic Era. It also took a long time for life to fully recover from this event, with some estimates suggesting it took as long as 10 million years for biodiversity to return to pre-extinction levels.
As we face our own environmental challenges today, understanding events like the Great Dying can help scientists predict potential outcomes and develop strategies to prevent similar scenarios from occurring due to human-induced climate change.
Image Credit: Art by Matt Celeskey