North American scimitar – homotherium serum

Following its favorite snack, the woolly mammoth, it was said north American scimitar toothed cats may have migrated across the bering land bridge and spread throughout north America.

Discovery was by the famous French paleontologist Baron Cuvier, in 1824. He was the first to describe the serrated teeth of homotherium from deposits in France, thinking they belonged to a bear, or something else. They had less fossils than there cousins the sabre tooth cats, and it was believed they originated from them somehow, or, other cat beasts millions of years ago. Emilio Fabrini proposed the name homotherium in 1890. Translated in greek as ‘same beast’.

In north American, around 1893, the scimitar cat was first described by E.D. Cope as dinobastis serus. Its remains, from deposits dating between about 1.5 million and 10,000 years old, are known from Yukon to Florida. By 1962, they had adopted homotherium serum.

There is little doubt the “same beasts, or scimitars”, like sabre tooth cats, were derived from the late pliocene – early pleistocene (about 2 million years). And in turn, derived from machairodus, even longer ago.

Biology: 6 feet and 300 pounds?
Modern lions are similar size to scimitar but without the slender limbs. “same beasts” had 4 inch wide serrated teeth to inflict wounds. And, unlike there sabre tooth cousins teeth, which may have been a sexual attraction in finding mates, there shorter wider, finely serrated teeth, made a more powerful slicing tool. They had long legs, and sloping back. It allowed scimitar to travel up to 65km/h. See enlarged nose and nostrils? These cats were sneaky, sensory killing machines.

Actual skeletons of ‘same beasts’ suggests that h. serum is built for short bursts of speed, as well as agility. The first neck of the vertebra helped to support there massive muscles used to depress the head and teeth to inflict a killing bite. The pelvic region, including the sacral vertebrae, are bear-like. As is the short tail composed of 13 vertebrae. About half the number in long-tailed cats. Such features suggest ambushing and coming from behind.

Gassaway fissure and Friesenhahn caves:

The recovery adults and there cubs from caves in Texas and Tennessee suggest these animals lived in dens, possibly in family groups. This is further supported by the association of multiple mastodons found inside them. And, unlike dens of some of the other cat like species like sabretooths, mountain lions and others.

Did u see a scimitar cave den?

A partly dis-articulated skeleton of a juvenile, found with two complete adult skeletons, from Gassaway Fissure, Tennessee, estimated to have been 2 to 4 months old at death, probably represents a cub born in a denning cave.

Of great interest, were between 300 and 400 juvenile mammoths found in the caves. The majority were just 2-year olds. probably such calves became easy prey for scimitar cats. Indeed, the association of scimitars, homotherium or “same beasts” with proboscideans (elephants and mastodons) and rhino remains constant. It reinforces the idea that ‘same beasts or scimitars’ preyed selectively on these tough-skinned animals. As well long nose peccary’s, and turtles which were found in Texas, these “same beasts” would probably take down anything smaller than a young mastodon or rhino. Given the meal size, it could last there family weeks, or more.

What is a scimitar hunt?

Picture a grassy parkland like environment where mammoth or prey are usually found.    Leaving its cave shelter or den, from stalking, the felid cat beast approaches a small heard of mammoths.    After crouching behind small juniper tree brushes, it selectively finds its prey. A young 2 year old columbian mammoth playing slowly at distance from the pack. So starts a blindsidingly quick rush alongside the mammoth calf (pic). The cat jump attacks, snowballing its prey over, its deep claws pierce the shoulder of the mammoth so bad it is screaming.   Straddling the chest of the crying woolly calf, the beast cat slashes the exposed mammoths neck with its scimitars. Immediately the child mammoths mother, and rest of the herd move forward, trumpeting towards action. Within minutes the mammoth calf quickly bleeds to death, while the ‘cat beast” retreats to cover nearby.    When the herd finally abandons the young mammoth kill, the cat cautiously approaches, dragging the body in its powerful jaws, into its cave.  There it dismembers and eats its prey, shearing and breaking down large chunks of flesh with its fangs and gulping them down.    Only its baby teeth and its limb bone sockets are left, with telltale scratches and marks left to commemorate the scimitar cats killing power.   

American lion bones have been found in the trash heaps of paleolithic native Americans, suggesting that human predation contributed to its extinction.

In this vast land, competing for food and territory. Cave lions never have it easy. panthera atrox means “cruel” or “fearsome panther” in latin. These critters were 125% the size of modern lions, making them one of the largest and most competitive of the known felids.    They differ from european cave lions, being discovered later, lasting longer and that the proposed subspecies scientist included are different. Would you mess with a 900lb cat?

Natchez, Mississippi origins

The first samples of the “cruel or fearsome panther” collected, were announced by the American philosophical society and William Henry Huntingtion Esquire. Although only manible and few molars,  on April 1, 1836. They were placed with Huntington’s collection in the academy of natural sciences in Philadelphia.   

Would you have come forward?

No major discoveries were published until 1853. When using samples from Livermore, California, Joseph Leidy was able to identify a greater skeleton. Ongoing, in 1907, more than 100 years after finding while mining, the American museum of Natural History and College announced they had found skeletons in Kotzebue, Alaska. Further south, in Rancho La Brea, California, a large ‘cruel or fearsome panther” skull was excavated and later described around 1909. So began the rush for pathera atrox, acl, or cruel fearsome panthers.

At least 80 ACL’s were pulled from La Brea tar pits

Throughout the early to mid 1900s, dozens of fossils of panthera atrox or “cruel fearsome panthers” were excavated at La Brea, including many post cranial elements. In 1932, these fossils were described by Merriam & Stock in detail, who completed many previously named taxa. A number of associated skeletons were also reviewed giving a comprehensive view of the taxon. Check out more blog entries here: smiloden, giant short faced bear.


Like modern lions, the ‘cruel fearsome pather or acl’ inhabited savannas and grasslands. In different circumstances American lions could have lived under cold climatic conditions. Especially those with shelters or caves, like where there was protection from the seasonalities: rain, snow, wind and cold conditions. It did not like forests like jaguars though. Scientists have imagined, given its size, it would have lined its den with sticks leaves and branches like some modern cats.


Lifespan was 340-11 thousand years ago. From nose to tail, the ‘acl or cruel fearsome panther’ were around 7 feet length, and 48 inches shoulder height. Smaller than smilodon (sabre tooth cat), and much smaller than the flat nose or bulldog bear. Most were around 550lbs, though some were 800, or even one specimen was recorded at 930lbs.

Though many pictures include orange, white, black, yellow, and brown. Skin from Argentine Patagonia indicate that the animal was reddish in color. Cave paintings from El Ceibo in Argentina seem to confirm this, and reduce greater confusion with jaguars. No matter the case, these critters are tough, and it appears humans eventually contributed to there decline. Though the end of the pleisocene epoch and beginning of the holocene was expected as the eventual contributor, 11,700 years ago to its decline. Witnessing mountain towns, it’s vindicated that modern mountain cats are still fearsome, many times stalking pedestrians and pets then disappearing altogether.


American lions were big and hungry. It was likely they preyed mostly on mammoths, bison, deer, horses, camels, tapirs, and smaller mammals. They were opportunistic, warm blooded killers. Defending themselves, for food and territory, American cave lions did whatever it took. They may have even attacked each other. No one ever said life was going to be easy.

American cave skeleton from La Brea tar pits 1111