Well-preserved remains of saber-toothed kitten found frozen in Russian tundra, researchers say

Scientists have discovered a pristine fossil of a mummified saber-toothed kitten that had been frozen in the Russian tundra for about 37,000 years.

The carcass of a large cub estimated to be about 3 weeks old was found encased in a block of ice in the Republic of Sakha, located in Russia's Far East, along the Badyarikha River in 2020, according to a paper published in Scientific Reports on Thursday.

Radiocarbon dating puts the cub, of the Homotherium latidens species, in the Late Pleistocene period, according to the researchers. The remains contain the head and the anterior part of the body preserved to the edge of the chest.

The mummy's head was especially well-preserved, and the forelimbs of the mummy were preserved almost completely, the paper states. The kitten's foot pads and claws are preserved on the plantar surface of the front paw, and all claws -- sharp and strongly curved -- are preserved on the fingers.

It is unclear how the cub died, the researchers said, adding that its features show it was well-adapted to living in a cold climate.

Findings of frozen mummified remains of mammals from the Late Pleistocene period are "very rare," the researchers said.

"For the first time in the history of paleontology, the appearance of an extinct mammal that has no analogues in the modern fauna has been studied," the paper states.

Homotherium Fabrini, also known as saber-toothed cats or "tigers," are characterized by their enormous, deadly-sharp canines that paleontologists believe were used to grab and hold onto prey or deliver a fatal ripping wound to the belly or throat of a prey animal.

They are estimated to have gone extinct at the end Pleistocene period about 12,000 years ago, with fossils found all over Eurasia, Africa and the Americas.

When comparing the remains to a modern-day lion cub of a similar age, researchers found "striking morphological peculiarities," according to the paper. Physical differences of the extinct species included an unusual shape of the muzzle -- with a large mouth opening and small ear -- a "very massive" neck region, elongated forelimbs and a dark coat color. The mummy's body is covered with "short, thick, soft, dark brown fur," with hair about 20 millimeters to 30 millimeters long, the researchers described.

Over the past 10 years, mummies of various animals have been discovered in Russia's Indigirka River basin, of which the Badyarikha River is a tributary, the researchers said. "Numerous" bones of mammoths have been collected in the region, according to the paper.

The newest finding of "the Badyarikha mummy" radically expands the understanding of distribution of the genus and confirms its presence in the Late Pleistocene of Asia