37,000-year-old saber-toothed 'kitten' found in Arctic permafrost, revealing new species insights

The saber-toothed kitten.

Russian scientists have unveiled the remarkably preserved remains of a juvenile saber-toothed cat, offering unprecedented insights into the species that roamed the Arctic during the Late Pleistocene period. The mummified cub, belonging to the species Homotherium latidens, was discovered in 2020 in permafrost on the banks of the Badyarikha River in Yakutia, Russia's Siberia region.

The findings were reported by NBC News, Sky News, and Gizmodo, among others.

According to a paper published in Scientific Reports, the cub is approximately 37,000 years old, with radiocarbon dating yielding an age of about 31,800 years. The researchers explained that findings of frozen mummified remains of Late Pleistocene mammals are "very rare," highlighting the significance of this discovery.

The cub was just three weeks old when it died, determined by the degree of development of its bones and teeth. Its body was recovered intact, including the entire head, one forelimb, shoulders, ribcage, and one hind leg, providing an unprecedented opportunity to study an extinct mammal with no modern analogues. The well-preserved state of the mummy allowed scientists to observe features that had previously been unknown.

Physical differences of the extinct species included an unusual shape of the muzzle—with a large mouth opening and small ears—a "very massive" neck region, elongated forelimbs, and a dark coat color. The researchers noted that the cub's features show it was well-adapted to living in a cold climate, which are classic adaptations typical of animals in such environments.

The mummified body is covered with "short, thick, soft, dark brown fur" with hair about 20–30 mm long, and the fur on its back and neck is longer than on its legs. It had dense tufts of fur at the corners of its mouth and whiskers: two rows on the upper lip. The cub still has its whiskers and claws attached. Its paws are relatively wide compared to those of its living relatives, aiding in movement through snowy terrain.

One of the striking features is the presence of an enlarged premaxillary bone, allowing for an "expanded row of large cone-shaped incisors." However, the individual was too young for its impressive fangs to have grown, as it still had some of its milk teeth. The researchers stated, "The difference in (neck) thickness is explained by the large volume of muscles, which is visually observed at the site of separation of the skin from the mummified flesh."

By comparing this species to a living relative—modern lion cubs about three weeks old—researchers discovered key differences, including an unusual muzzle shape, a wide mouth opening, small ears, elongated forelimbs, and a robust neck region. The cub's neck is "longer and more than twice as thick" as that of a modern lion cub, and the mouth opening is about 11% to 19% bigger.

The front paw is perfectly preserved, with its foot pads and claws intact on the plantar surface. Notably, the cub lacks carpal pads, which are thick skin pads found on the back of the wrist joint that act as shock absorbers and help walk in deep snow. This adaptation suggests that saber-toothed cats were well-suited to moving through snowy environments.

The team used CT scanning to reveal the skeletal structure non-invasively. Images from the study show the outer coat of the cub and a tomographic scan revealing the structure of the bones. The mummy's skull was slightly deformed, but its well-preserved right side allowed the team to reconstruct its shape. The researchers added, "Thus, for the first time in the history of paleontological research, the external appearance of an extinct mammal that has no analogues in the modern fauna has been studied directly."

While the exact circumstances of the cub's death remain unknown, the discovery provides invaluable resources for understanding these extinct animals. The researchers noted that this specimen is proving to be an invaluable resource, as it allows for a deeper understanding of their appearance and morphology.

Alexey Lopatin of the Russian Academy of Sciences in Moscow and colleagues stated that "the studied frozen mummified cub confirms the modern reconstructions of the life appearance of Homotherium." "It also complements the external features—the fur color, the muzzle size, ear size, the shape of the foot pads, etc. These characters cannot be seen on skeleton remains," he added.

Homotherium latidens is the only species in its genus known to inhabit Eurasia at this time and lived in a drastically different world than the one we know. The Late Pleistocene is known for massive changes to the Earth's climate, including the Last Glacial Maximum, which peaked around 26,000 years ago. Homotherium latidens, also known as saber-toothed cats or "tigers," inhabited vast areas of Eurasia, Africa, and the Americas, with specific species adapting to different regions.

They are characterized by their enormous, deadly-sharp canines, which paleontologists believe were used to grab and hold onto prey or deliver a fatal ripping wound. However, this particular specimen was too young for its impressive fangs to have grown. The findings confirm that the features observed in adult specimens were already present at a very young age.

Most Homotherium remains have been discovered in North America, making this latest discovery a valuable opportunity to shed light on the Eurasian branch of the genus. The discovery of the mummy of Homotherium latidens in Yakutia radically expands the understanding of the genus's distribution and confirms its presence in the Late Pleistocene of Asia.

The researchers are already working on another paper that will discuss the cub's anatomy in more detail. They noted that "some new unique mummified specimens have already been found in Yakutia," where the cave lion and saber-tooth cat cubs were found.

In recent years, several animal species have been excavated from the permafrost of Siberia, including woolly rhinoceroses, mammoths, wolves, cave lions, and birds. These discoveries represent an open window to a distant era, allowing us to see with our own eyes a fragment of the past and appreciate the biodiversity of a vanished world, preserved in the eternal frost of Siberia.

This study offers new insights to better understand the prehistoric world and its mysteries still hidden in the ice. Thanks to this discovery, researchers now have a unique window into the development of this iconic species. The incredible preservation of this specimen reveals interesting ways in which the large feline adapted to its icy environment.

This article was written in collaboration with generative AI company Alchemiq