Archaeologists have unearthed the largest predator to have lived on Earth in the pre-dinosaur era.
The researchers discovered two new sabre-toothed carnivores while studying fossils found in Russia.
The newly-discovered predators have shed new light on what happened to animal life between two mass extinction events, which took place between 260 million years ago and 252 million years ago.
Scientists says the fossils reveal how the pecking order of prehistoric animals changed in the 18 million year window.
The carnivores are part of a group known as ‘protomammals’, which also includes tusked herbivores, burrowing insectivores and sabre-toothed predators, and eventually evolved into some of the animals still seen on Earth today.
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Archaeologists have found two sabre-toothed carnivores which roamed Earth before dinosaurs existed. These predators have shed new light on what happened between two mass extinction events between 260- and 252 million years ago
The first of the two new species, named Gorynychus masyutinae, was a wolf-sized predator now believed to be the largest carnivore of the era.
The second new species, Nochnitsa geminidens, was a smaller, long-snouted meat-eater with needle-like teeth.
Gorynychus belongs to a subgroup of protomammals called therocephalians (‘beast heads’), while Nochnitsa belongs to a different subgroup, the gorgonopsians (‘gorgon faces’).
Around 248 million years ago, the Permian period ended and the Triassic period started on Earth.
Marking the boundary between these two geologic eras is the Permian mass extinction, nicknamed ‘The Great Dying’.
This catastrophic event saw almost all life on Earth wiped out.
Scientists believe around 95 per cent of all marine life perished during the mass extinction, and less than a third of life on land survived the event.
In total, it is believed that 90 per cent of all life was wiped out.
All life on Earth today is descended from the roughly ten per cent of animals, plants and microbes that survived the Permian mass extinction.
Previously, it was believed a huge eruption blanketed the Earth in thick smog, blocking the sun’s rays from reaching the planet’s surface.
However, new findings suggest a massive volcanic eruption that ran for almost one million years released a huge reservoir of deadly chemicals into the atmosphere that stripped Earth of its ozone layer.
This eradicated the only protection Earth’s inhabitants had against the sun’s deadly UV rays.
This high-energy form of radiation can cause significant damage to living organisms, causing the death toll to skyrocket.
By analysing the fossil record, researchers have managed to gain a better understanding of ecosystems after mass extinctions.
At the time of the catastrophic late-Permian extinction, some 252 million years ago, the top predators were tiger-sized, sabre-toothed gorgonopsians.
Also around this period, therocephalians were typically small insectivores.
However, these roles were reversed by the mid-Permian ecosystems, when the size of sabre-tooth beasts decreased dramatically.
‘In between these extinctions, there was a complete flip-flop in what roles these carnivores were playing in their ecosystems – as if bears suddenly became weasel-sized and weasels became bear-sized in their place,’ says Dr Christian Kammerer from the North Carolina Museum of Natural Sciences.
The discovery of these new species will provide the first evidence that there was a worldwide turnover in predators after the mid-Permian extinction.