Last week, researchers in Russia published a paper on a rare find: a mummified cub, from about 30,000 years ago. The mummy—complete with head, fur, paws, and the upper half of its body—is the first glimpse ever at the external morphology of an extinct cat with no present-day analogs.
It was discovered in 2020, frozen in an ice chunk on the Badyarikha River in the far northern Yakutia region of Russia. After laboratory analysis, researchers are calling it a Homotherium latidens, or saber-toothed cat.
The cat is a youngster—only about three weeks old by the scientists’ best guess—but it still offers some ideas about what the species might have looked like. Notably, all the claws are preserved on the front paws. They’re sharp and curved, ranging from about 7 to 10 mm in length. The paws are rounded and missing carpal pads (the little nub that cats and dogs have), meaning the species was likely well adapted to walking in the snow, and therefore, likely lived in areas with cold climates.
Overall, the specimen has thick, brown hair and a short body with long limbs—again, a possible adaptation for walking in snowy areas. Two rows of broken whiskers protrude from the cat’s face. Unfortunately, the researchers note, the cat’s eyelashes were not preserved. Still, the mummy is a unique insight into what the extinct cat species might have looked like. No other fully-preserved specimen has ever been found.
The majority of the paper is filled with technical descriptions and diagrams of the mummy, describing the size and shape of every bone, tooth, and facial feature. For example, the researchers write: “One of the striking features of the morphology of Homotherium, both in adults and in the studied cub, is the presence of an enlarged premaxillary bone, containing a lateromedially expanded row of large cone-shaped incisors that form a convex arch.” That’s to say, the cat had a line of sharp teeth curving across its mouth.
Researchers were particularly interested in how this ancient cub compared to its modern relatives. They studied a three-week-old lion (Panthera leo) for this analysis, and they made some interesting observations. The muzzle is one of the most noticeable points of distinction. The specimen has a much larger mouth opening and smaller ears. Its neck is what the researchers describe as “massive.” It’s longer and more than twice as thick as a modern lion cub, which researchers say is due to its “large volume of muscles.”
The mummy’s forelimbs are 18-23% longer than a lion cub’s, but based on what was preserved of the mummy’s torso, its body would have been about the same length or even a little shorter. This, they say, matches up with what we thought we knew about adult saber-tooth cats as compared to lions. Researchers also noted that the coat color is quite a bit darker than a lion’s though they don’t explain how they could tell that the color had stayed the same since it’s been in the ice.
In terms of what else can be garnered from the mummy, the lead author (a paleontologist in Russia) told news outlet Gizmodo that “DNA can be extracted, and this is one of the next stages of our research.” The genetic information could be referenced against that of other ice-age species to determine exactly how Homotherium fits in with other feline species from the epoch. That would include two other frozen kittens discovered in 2018 in Russia, with one dating back to nearly 44,000 years ago. While similar to the more recent mummy, the two kittens are thought to belong to a separate species.
The late Pleistocene, when the mummy is believed to have lived, was characterized by the presence of many large mammal species and large extinction events. Mammoths, mastodons, and saber-tooth tigers roamed the northern hemisphere. Giant beavers, sloths, and turkeys walked the landscape. Most of the megafauna are hypothesized to have gone extinct from human hunting or a changing climate—the latter resulting in a loss of habitat and forage.
While scientists have a pretty good understanding of the creatures that were alive, they’re still piecing the details together, and every little piece of evidence helps. The lead author of the paper says he’s hopeful that more frozen, mummified cats will be discovered in the near future.
Images via Lopatin et al., Scientific Reports 2024.
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