Perfect preservation: 28,000-year-old frozen cave lion cub found in Siberia
A team of international researchers from Sweden, Japan, and Russia have confirmed that a cave lion cub mummy unearthed from the permafrost in Siberia in 2017 was an infant female that lived 28,000 years ago. This was announced in a Stockholm University press release .
This female cave lion cub was one of two mummified cubs dug up along the banks of the Semeyuelyakh River (northeastern Siberia) in 2017 and 2018 by ivory traders looking for valuable mammoth tusks. These fortune seekers use high-pressure blast hoses to blow holes in the frozen ground, where many tusks have been found. While this destructive practice is highly controversial, it has led to the discovery of many extraordinarily well-preserved ancient animal fossils and frozen mummified bodies.
Figure 6 from the Quaternary study: The appearance of the frozen cave lion cub mummies: (a) female Sparta; (b) male Boris. Photos of lion cubs’ heads from the side: (c) Sparta; (d) Boris; (e) Sparta mummy as seen from above; (f) dark brown ‘brush’ of Sparta’s tail. ( Quaternary journal )
How Research Revealed So Much About These Cave Lion Cubs
The two cave lion cubs , which scientists named Sparta (the female) and Boris (the male), were found just 49 feet (15 meters) apart and were originally believed to have been a part of the same family. But while radiocarbon dating revealed Boris to have lived more than 43,000 years ago, tests have now proven that Sparta lived 15,000 years later.
In contrast to her antiquity, Sparta was found in a state that suggested she was hibernating or in a state of suspended animation. Her frozen body was still completely covered with golden fur, and her skin, teeth, soft tissue and whiskers were all perfectly preserved.
Despite her lifelike appearance, however, the young cave lion represents a species of big cat that has been extinct for 12,000 years.
“Sparta is probably the best-preserved Ice Age animal ever found, and is more or less undamaged apart from the fur being a bit ruffled,” said Love Dalén, an evolutionary geneticist from the Center for Paleogenetics in Stockholm, Sweden, and co-author of the new study on the cubs. “Boris is a bit more damaged, but still pretty good.”
A Eurasian cave lion with a reindeer, as imagined by painter Heinrich Harder. The Siberian cave lion cubs would have looked like this had they reached maturity. Source: Heinrich Harder (1858-1935) / Public domain
While far from tiny (cave lions of any age were about 12 percent larger than modern lions ), the mummified cubs were only about one or two months old when they died.
The research team found no evidence to suggest they were killed by predators. However, they did find signs of damage on the cubs that suggest they either fell a significant distance to their death or had something heavy fall on top of them. CT scans showed signs of skull damage, rib dislocation, and other skeletal injuries consistent with a sudden, catastrophic accident of some type.
“Given their preservation they must have been buried very quickly,” Dalén concluded. “So maybe they died in a mudslide or fell into a crack in the permafrost.”
It is fascinating to note that while they seem to have met a very similar fate, the two small lion cubs lived 15,000 years apart in time. Whatever force of nature claimed them must have been something that occurred commonly in the Semeyuelyakh River region.
The range of predators and prey, including Eurasian cave lions, on the Siberian Plain during the last major Ice Age. ( Tsarizim)
The Cave Lion’s Life on the Siberian Plains
The cold, vast, deserted tundra of Siberia might seem like an unusual place to find the mummified remains of a cave lion. But during the last Ice Age, animal life was abundant in Siberia. There were large populations of mammoths, bears, rhinoceroses, bison, antelopes, wolves, and many other species. Predators like cave lions were able to survive and thrive in such an environment, always finding plenty to eat.
The new study, which was sponsored by Stockholm University’s Center for Paleogenetics and introduced in an article in the journal Quaternary, found both similarities and differences between ancient and modern lions. One notable difference is the thickness of the fur: the Ice Age cubs had a thick undercoat and denser fur overall, which represented an obvious adaptation to the cold and windy conditions of the plains of Siberia .
While cave lions weren’t that much longer or taller than full-grown modern African lions, they were built more powerfully and could therefore capture larger prey. They may have hunted in packs, meaning that even the largest animals like the mammoth wouldn’t have been safe from them.
The Eurasian cave lion (their full name) roamed far and wide across the steppes of northern Europe and Asia, and they also reached what is now North America by crossing over the Bering Strait land bridge when sea levels were low during the last Ice Age.
The range, size and appearance of Panthera spelaca or the Eurasian cave lion. ( DinoFax)
Interestingly, the name cave lion has nothing to do with these lions taking shelter in caves. The caves of Siberia were popular hibernation spots for ancient bears, and several intact skeletons of adult cave lions have been found in the same locations. It seems that cave lions would sometimes try to attack and eat hibernating bears when food sources were scarce in the wintertime. The presence of their skeletons in bear caves suggests this strategy sometimes backfired (when hibernating bears awoke and successfully defended themselves).
It isn’t known exactly why cave lions—and many other large animals—went extinct at the end of the last Ice Age. But climate change likely played a critical role.
Warming temperatures and rising sea levels were a consequence of the melting of the ice sheets, and this caused ecosystems to undergo dramatic changes in many regions. It seems that some animals, like the cave lion, were not able to successfully adapt to different environments.
It is likely that the animals they preyed on disappeared from northern lands first, with the increasingly hungry cave lions following them into extinction soon after. The last cave lion populations survived by retreating to the Bering Strait land bridge about 13,000 years ago but went extinct sometime before the land bridge was flooded by the rising sea.
Tracking Lion Evolution through Time
According to Love Dalén, the scientists will now be working to fully sequence Sparta’s DNA, which has also been extremely well preserved just like the rest of her. Boris’s DNA will be sequenced as well, and the fact that he lived 15,000 years earlier will make for informative comparisons.
The data the researchers obtain could help reveal much about the evolutionary history and lifestyle of the cave lion. It will certainly reveal meaningful details about the cave lion’s relationships to other lion species (and cat species) both past and present.
Top image: A closeup of the head of the female Siberian cave lion cub mummy now known as Sparta. (Love Dalén / Stockholm University )