Sabre-Toothed Marvels: Ancient Mammals with Bear-Sized Frames and 5-Inch Canines Unveil Surprising Link to T. rex’s Meat-Eating Design

Gorgonopsians — the first sabre-toothed animals — had 5-inch canines ‘like steak knives’ with a saw-like design once though unique to meat-eating dinosaurs.

Sabre-toothed gorgons that lived before dinosaurs bit each other in the  face to assert dominance | Daily Mail Online

US, UK and Canadian experts found that the bear-sized mammals from 250 million years ago had serrated teeth made of enamel and dentine, like Tyrannosaurus rex.

However, the primitive beasts were tearing into the flesh of their prey more than 166 million years before the notorious ‘king of the dinosaurs’ walked the Earth.

Fossils: Sabre-toothed mammals from 250 million years ago had 5-inch canines  'like steak knives' | Daily Mail Online

Despite having evolved from an earlier cat-size mammal, the gorgonopsians grew to around 10 feet in length — but were nevertheless nimble and deadly predators.

Gorgonopsians — the first sabre-toothed animals — had 5-inch canines ‘like steak knives’ (depicted) with a saw-like design once though unique to meat-eating dinosaurs

Despite having evolved from an earlier cat-size mammal, the gorgonopsians grew to around 10 feet in length — but were nevertheless nimble and deadly predators. Pictured, the complete skeleton of a gorgonopsian of the species Sauroctonus parringtoni

‘Our study finds a similar [dental] arrangement in sabre toothed gorgonopsians [as in bird-like dinosaurs,’ said paper author and palaeontologist Megan Whitney of the University of Washington, in Seattle.

Fossils: Sabre-toothed mammals from 250 million years ago had 5-inch canines  'like steak knives' | Daily Mail Online

‘This reveals this carnivorous specialisation not only started in the Permian, long before the rise of dinosaurs, but also in a forerunner of mammals.’

Dr Whitney and colleagues found that the tissue of gorgonopsian teeth folded along their blade-like cutting edges — forming a series of blade like serrations.

This would have allowed the sabre-toothed clade to easily tear apart the hides and flesh of other early mammals and reptiles — much in the same way modern diners use steak knives to cut up meat.

Gorgonopsians thrived for around 13 million years until being wiped out in the world’s biggest ever mass extinction at the end of the Permian period, around 252 million years ago — 22 million years before the first dinosaurs appeared.

The results show, therefore, that dinosaurs and gorgonopsians developed their deadly, saw-like teeth independently of each other — with the mammals being first.

In fact, gorgonopsians are closer related to humans than they are to dinosaurs.

‘Our finding shows it happened more on the mammal line as opposed to the reptile line and that it happened much earlier than we previously thought since these animals are much older than the theropod dinosaurs,’ said Dr Whitney.

‘What we are seeing is this really cool instance of convergent evolution,’ she added.

The significance of the finding, the researchers explained, lies in the timing of the appearance of the complex tooth structure — which was early in the evolution of the so-called amniotes, a group of animals that includes both reptile and mammal lines.

‘It is a very complicated way to build a serration because it involves two different tissues making really complicated folds,’ said Dr Whitney.

‘Typically, we associate that with time, right? The more time you have for evolution to take place, the more we think there’s the ability to evolve complicated traits.’

‘What we are finding here is that actually these animals early in amniote evolution were able to evolve a very complicated and specialised structure.’

US, UK and Canadian experts found that the bear-sized mammals from 250 million years ago had serrated teeth made of enamel and dentine, like Tyrannosaurus rex. Pictured, the skull of a sabre-toothed Gorgonopsian

The primitive beasts were tearing into the flesh of their prey more than 166 million years before the notorious ‘king of the dinosaurs’ walked the Earth. Pictured, the serrated teeth of a  fossilised Gorgonopsian specimen

‘What is surprising is the type of serrations in gorgonopsians are more like those of the meat-eating dinosaurs from the Mesozoic era,’ said paper author and palaeobiologist Aaron LeBlanc of King’s College, London.

‘It means this unique type of cutting tooth evolved first in the lineage leading to mammals, only to later evolve independently in dinosaurs.’

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‘Broadly, the group is really interested in looking at these hidden features and trying to shed light on a more complicated evolutionary history in the evolution of teeth than I think we have previously recognised.’

The full findings of the study were published in the journal Biology Letters.

‘What is surprising is the type of serrations in gorgonopsians are more like those of the meat-eating dinosaurs from the Mesozoic era,’ said paper author and palaeobiologist Aaron LeBlanc of King’s College, London. ‘It means this unique type of cutting tooth evolved first in the lineage leading to mammals, only to later evolve independently in dinosaurs.’ Pictured, a comparison of tooth serrations in (from L-R) a therapod dinosaur, Dimetrodon, a gorgonopsian and a sabre-toothed tiger