An iconic gorgonopsian known as Smilesaurus existed in what is now South Africa during the late Permian period.
According to new study, claims of a “gorgon” global extinction at the end of the Permian epoch were significantly overblown. Scientists recently discovered that some of these strange creatures known as “gorgons” lived until the Triassic period, despite the widespread belief that they perished along with the majority of other Earthly life at the time. They became a “dead clade walking,” according to the team, because they didn’t live for very long.
According to an examination of three fossils discovered in the South African Karoo Basin, the gorgonopsians, the main predators during the late Permian period, were able to escape the “Great Dying.” About 90% of all species perished during this catastrophe, also known as the end-Permian extinction, which occurred about 251.9 million years ago. Gorgonopsians were an exception, but even if they survived, they didn’t have very good prospects.
According to project co-researcher Christian Kammerer (opens in new tab), the research curator of paleontology at the North Carolina Museum of Natural Sciences in Raleigh, “‘dead clade walking’ is a term used in extinction studies that refers to when a group of organisms technically survives a mass extinction, but is so damaged by it that they never recover, and linger on for a little while before finally disappearing,” said Live Science in an email.
After a major extinction, dead clades may persist for millions of years, but they “never re-diversify or acquire large abundance in ecosystems, thus they are basically already “dead,” from a macroevolutionary perspective,” he said.
The study has not yet been peer-reviewed and was presented on Nov. 3 at the Society of Vertebrate Paleontology’s annual conference in Toronto.
a late Permian Cyonosaurus specimen on display in Cape Town, South Africa’s Iziko South African Museum.
Long before the dinosaurs appeared during the Triassic period about 240–230 million years ago, there were creatures called gorgonopsians, which were named after the legendary and terrifying Greek gorgons, whose appearance could turn people to stone.
The gorgonopsian partial skull from the Karoo Basin, which dates to the Induan age of the Triassic period, was known to the researchers (251.9 million to 251.2 million years ago). That skull had been disregarded by other academics because they believed it had been misdiagnosed or improperly dated. But according to Kammerer and the lead author Julien Benoit (opens in new tab), a senior researcher of paleontology at the Evolutionary Studies Institute of the University of the Witwatersrand in Johannesburg, a recent investigation showed that it was “definitely a gorgonopsian,” possibly from the genus Cyonosaurus.
The team next examined two other specimens from the Karoo Basin, which were probably also Cyonosaurus members. The Permo-Triassic boundary is crossed by two of the three gorgonopsian specimens, while an early Triassic stratum is the location of the third specimen.
A Cyonosaurus gorgonopsian’s fossil remains can be found at the Iziko South African Museum in Cape Town, South Africa.
Cyonosaurus fossils can be found in Cape Town, South Africa, at the Iziko South African Museum.
Cyonosaurus may have survived the mass extinction because of its diminutive size, widespread distribution, and adaptable feeding. The fox-sized carnivore was one of the tiniest gorgonopsians ever discovered. It had a narrow, elongated snout that was jam-packed with teeth. Small, generalist predators are more likely to survive catastrophic disasters because they can adapt to changing ecosystems more effectively than large, specialised predators, according to Kammerer. Cyonosaurus, he continued, “would be the gorgonopsian that we would hope may persist until the Triassic.”
After the mass extinction, biodiversity in the Karoo Basin plummeted, and the population of the herbivorous, tusked Lystrosaurus, which existed during some of the Permian and Triassic periods, exploded. Therefore, Cyonosaurus probably did not run out of prey, Benoit wrote in an email to Live Science.
The team stated that research is ongoing and “additional investigation of these sites is warranted.” But according to the data, gorgonopsians persisted into the early Triassic, which the researchers said in their conference abstract is about as remarkable as a tyrannosaur surviving an asteroid strike to Earth.
However, because Triassic gorgonopsians were uncommon and only represented by one genus, the researchers concluded that this dead clade walking “should still be regarded a victim of the end-Permian mass extinction.”
