New photographs of a pair of cave lion cubs found frozen in Siberia give an unprecedented look at a species that has been extinct for about 10,000 years.

Russian researchers revealed new details about the cubs in a press conference on Tuesday, including how they were found, and how they died. (See "Frozen Cave Lion Cubs from the Ice Age Found in Siberia.")

Collectors unearthed the cave lions while looking for mammoth tusks in Yakutia, Siberia, and at first were not sure what they had found. They placed the cubs in a glacier to keep them frozen, and then sent them to scientists in Yakutsk for analysis.

Nicknamed Uyan and Dina for the Uyandina River where they were found, the kittens will provide scientists with more details about the lions that roamed Eurasia and North America during the most recent Ice Age. They are the first prehistoric cats to be found in such an exceptional state.

The cubs were only two to three weeks old when they perished, says Sakha Republic Academy of Science paleontologist Albert Protopopov. They were so young that their baby teeth had not yet started to poke out from their gums.

Most likely, Protopopov says, the cubs died when the soil of their den collapsed. While tragic, the way Uyan and Dina died played an important role in their preservation, keeping them frozen for over 12,000 years until flooding this past summer exposed them.

View Images Scientists estimate that the cubs were only a few weeks old when they died, possibly more than 12,000 years ago. Here, researcher Gennady Boeskorov of the Academy of Sciences of the Republic of Sakha examines a cub. Photograph courtesy of The Academy of Sciences of the Republic of Sakha (Yakutia)

But the real research has only just begun. Until now, the cave lion—a subspecies of Panthera leo related to today’s lions—was known only from bones and tracks. Uyan and Dina will provide the first look at the soft tissues of these cats, from the characteristics of their thick coats to the anatomy of their internal organs.

Protopopov also says that genetic analyses are in the offing. “We will be able to know the degree of kinship between cave lions and African lions,” he says.

The scientists also hope to use radiocarbon analysis to determine how long ago the cats died, thought to be at least 12,000 years, and additional studies will likely provide new insights into what they ate and how they adapted to the frigid conditions of the chilly steppe habitats they one prowled.