The frozen cub was about 3 weeks old with brown fur and broad paws for walking on snow. The first of its kind study showed "significant differences" to a baby lion.
Scientists have studied the frozen remains of a 35,000-year-old saber-toothed kitten for the first time and found "significant differences" compared to a modern-day lion cub.
The cub's mummified body was found in the Siberian permafrost in 2020, according to a study published in the journal Scientific Reports on Thursday. Researchers discovered pelvic bones, a femur and shin bones encased in a block of ice along with the frontal remains of the cub.
The extinct mammal's appearance is unlike any "in the modern fauna," the researchers wrote.
A group of scientists used radiocarbon dating to determine that the cub -- belonging to the species Homotherium latidens -- lived between 35,000 and 37,000 years ago.
Uncovering frozen remains from Late Pleistocene mammals is a rare occurrence. Paleontologists have typically had to base their conclusions on what these prehistoric predators looked like by studying their fossilized bones.
This time around, the frozen carcass was still covered in fur, including whiskers, mummified flesh and muscle, allowing scientists to study the size and placement of its ears, its large mouth and unusual-shaped muzzle, massive neck, elongated forelimbs and dark coat.
The scientists compared the remains of the saber-toothed kitten to that of a 3-week-old lion cub, Panthera leo, as well as the skulls of other juvenile lions.
They estimated its age based on the emergence of baby incisor teeth, which they compared to those of the lion cub.
The mummified cub's body was covered with a thick coat of soft, dark brown fur about an inch long, the researchers said. Its neck was longer and more than twice as thick as that of a modern-day lion cub.
The cub's forelimbs were almost completely preserved, revealing broad, furry paws suitable for walking in snow, and sharp, curved claws.
Saber-toothed cats roamed widely across Africa, Europe and the Americas for hundreds of thousands of years until about 10,000 years ago, when the ice age came to an end and their prey began to die out.
Unlike modern big cats, who have long legs and use their long tails for balance when running, saber-toothed cats were stocky with short legs -- better suited to ambush attacks where they would sink their saber teeth into their prey.