Fossils: Newly identified saber-toothed cat from 9 million years ago weighed 600 pounds

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A newly identified saber-toothed cat that lived in North America five to nine million years ago weighed about 600 pounds and could have made prey ten times its size.

American researchers named the ferocious feline ‘Machairodus lahayishupup’ to honor the Cayuse people, on whose land the original specimen was excavated.

In Old Cayuse, ‘Laháyis Húpup’ means old wild cat, while ‘Machairodus’ is a well-known genus of giant saber-toothed cats from North America, Africa, Eurasia.

The team believes the newly identified species existed early in the evolution of the saber-toothed cats, but more research will be needed to confirm this.

M. lahayishupup is also a relative of Smilodon – perhaps the best known of the saber-toothed cats – which became extinct about 10,000 years ago.

The new species was mainly identified by its huge forearms, a feature that saber-toothed cats used to subdue their prey.

A newly identified saber-toothed cat that lived in North America 5-9 million years ago weighed about 600 pounds and could have caught prey ten times its size.  Pictured: An artist's impression of M. lahayishupup eating a 'Hemiauchenia', a relative of the camel

A newly identified saber-toothed cat that lived in North America 5-9 million years ago weighed about 600 pounds and could have caught prey ten times its size. Pictured: An artist’s impression of M. lahayishupup eating a ‘Hemiauchenia’, a relative of the camel

M. LAHAYISHUPUP

Lived: 5-9 million years ago

Place: North America

From. weight: 272 kg (600 lbs)

Prey: Rhinos, sloths and hemiauchenia

The study was conducted by biologists Jonathan Calede of Ohio State University and John Orcutt of Gonzaga University in Spokane, Washington.

“We think these were animals that routinely shot bison-sized animals,” said Professor Calede.

“This was by far the largest cat alive at the time.”

The duo’s research stemmed from when Professor Orcutt was now a graduate student and saw a large upper arm bone at the University of Oregon Museum of Natural and Cultural History that had been vaguely labeled as belonging to a cat.

The researchers found another six uncategorized humeri in a variety of collections, including at the University of California Museum of Paleontology, the Texas Memorial Museum, and the Idaho Museum of Natural History.

In the latter case, the big cat’s forearm was accompanied by teeth, which are generally considered a gold standard for identifying new species.

The largest M. lahayishupup humeral fossils they found were over 46 cm (18 inches) in diameter and 4.3 cm (1.7 inches) in diameter.

In comparison, the upper arm bone of an average modern adult male lion is approximately 33 cm long.

An upper arm bone of the new species that was excavated in central Oregon and is now on display at the University of Oregon Museum of Natural and Cultural History

Biologist John Orcutt at work in the field

American researchers named the ferocious feline ‘Machairodus lahayishupup’ to honor the Cayuse people, on whose land the original specimen was excavated. In Old Cayuse, ‘Laháyis Húpup’ means ‘old wild cat’, while ‘Machairodus’ is a well-known genus of giant saber-toothed cats from North America, Africa, Eurasia.

One of the great stories behind it all is that we eventually discovered specimen after specimen of this giant cat in museums in western North America. They were clearly big cats, ”said Professor Orcutt.

“We started with a few assumptions based on their age, in the range of 5.5 to 9 million years old, and based on their size, because these things were huge.

“ What we didn’t have then, what we have now, is the test of whether the size and anatomy of those bones tells us anything – and it turns out they do. ”

To prove that that elbow portion of the humerus next to teeth can be used to distinguish types of big cats, the duo analyzed forearm specimens of jaguars, lions, cougars, panthers, tigers, and other extinct felines from museums around the world.

Professor Calede used software that allowed them to model each elbow and mark its defining features.

‘We discovered that we could quantify the differences on a fairly fine scale. This told us that we could use the shape of the elbow to distinguish types of modern big cats, ‘he explained.

Then we took the tools to the fossil record – these gigantic elbows scattered around museums all had one characteristic in common. This told us that they all belonged to the same species.

Their unique shape and size told us they were also very different from anything already known. In other words, these bones belong to one kind, and that kind is a new kind. ‘

The new species was mainly identified by its massive forearms, or 'humeri' - a feature saber-toothed cats used to subdue their prey.  Pictured: one of the humeri

The new species was mainly identified by its massive forearms, or ‘humeri’ – a feature saber-toothed cats used to subdue their prey. Pictured: one of the humeri

The researchers used the association between body weight and forearm size in modern big cats to make their estimates of M. lahayishupup body size.

They speculated on the nature of the ancient cat’s prey by taking into account the size and animals that lived in the surrounding region at the time – including giant ground sloths, rhinoceroses, and giant camel relatives called Hemiauchenia.

The experts noted that the only jaw specimen of M. lahayishupup known to date is of the lower jaw – and thus unfortunately does not include the iconic saber-shaped canines that Machairodus is known for.

However, Professor Orcutt said, “We’re pretty sure it’s a saber-toothed cat and we’re pretty sure it’s a new species of the Machairodus genus.

“The problem is, our understanding of how all these saber-toothed cats are related is a bit hazy, especially in the early stages of their evolution.”

In particular, researchers have not had the clearest picture of exactly how many types of giant cats existed in the past, Professor Orcutt explained.

The discovery that fossil cats can be identified based on their humeri alone may help improve this understanding, he added – as the ‘big, fleshy’ forearms of saber-toothed cats are the most common remains found in excavations.

The researchers found seven uncategorized humeri in various museum collections, including the University of California Museum of Paleontology, the Texas Memorial Museum, and the Idaho Museum of Natural History.  In the latter case, the big cat's forearm was accompanied by teeth (pictured) - widely regarded as a gold standard for identifying new species

The researchers found seven uncategorized humeri in various museum collections, including the University of California Museum of Paleontology, the Texas Memorial Museum, and the Idaho Museum of Natural History. In the latter case, the big cat’s forearm was accompanied by teeth (pictured) – widely regarded as a gold standard for identifying new species

“It is known that there were giant cats in Europe, Asia and Africa – and now we have our own giant saber-toothed cat in North America during this time,” said Professor Calede.

“There is a very interesting pattern of either repeated independent evolution on every continent with this gigantic body size in what is still a pretty hyperspecialized way of hunting.

Otherwise, we have this ancestral giant saber-toothed cat that has spread to all those continents. It’s an interesting paleontological question. ‘

The full findings of the study are published in the Journal of Mammalian Evolution.

THE MOST FAMOUS SABER-TOOTHED CAT: SMILODON

Pictured: an artist's impression of a jumping Smilodon

Pictured: an artist’s impression of a jumping Smilodon

Smilodon is a genus of the saber-toothed cat that lived about 2.5 to 0.01 million years ago in the forests and shrubs of the Americas.

It is popularly known as the saber-toothed tiger, although it is not closely related to modern tigers or other modern cats.

However, it was about the same size as today’s big cats, if built with a more robust frame.

A total of three species are known – S. gracilis, S. fatalis and S. populator – with most of the specimens found in the La Brea Tar Pits in Los Angeles, California.

It is thought to hunt by holding its prey still with its hefty forearms before delivering a deadly bite.

Smilodon’s prey is said to have included large herbivores such as bison and camels.

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