A cave filled with an incredible number of animal bones has been discovered in Siberia, from mammoths and bears to frogs and woolly rhinoceros. It’s pretty clear how all these Ice Age bones got here: a massive den of cave hyenas that dragged dozens of animals here for lunch.

Located near the Siberian city of Khakassia, the cave was home to an extinct hyena species about 42,000 years ago and is believed to be the largest cave hyena den ever discovered in Asia.

The researchers collected about 400 kilograms of bone from the cave and sent it for further analysis. Among the gnawed animal bones found here are mammoth, rhino, woolly bison, yaks, deer, gazelle, old brown bear, fox, wolf, some rodents, frogs, toads, birds and fish.

They also discovered the skulls of two cave hyenas, confirming their suspicions that this was a feeding ground for this predator.

“Rhinos, elephants, deer with characteristic bite marks. We also encountered a number of bones in anatomical order. For example, in rhinos the ulna and radius are found together. This suggests that hyenas dragged parts of the carcass into the burrow,” said one of the scientists.

“Another unique find is the large number of puppy bones in the cave. The fact is that the bones of large hyenas are often preserved, as the bones of young individuals are very fragile, loose and sensitive. Also, the same hyenas can bite them. You can even bite a whole skull of a young hyena, many We found his very lower jaw and milk teeth.”