Cave bears

The cave bear, Ursus spelaeus, lived in Europe from about 250,000 years ago to about 24,000 years ago. It shared an ancestor with the brown and polar bears, and its line split from theirs more than a million years ago. A large male weighed roughly 350 to 600 kilograms. It was named from fossils found in the Gailenreuth cave in Bavaria by Johann Christian Rosenmuller in 1794. Caves from Spain to Romania hold bones of thousands of individuals, many of them animals that died while hibernating.

Chemical analysis of bones and teeth shows that cave bears ate mostly plants, with little meat. They hibernated in caves for the winter, and many died there, so the remains piled up over thousands of years. Cave bear DNA was among the first ancient DNA recovered from an extinct animal, in the 1990s. Genetic studies by Gretzinger and colleagues in 2019 showed that numbers began to fall tens of thousands of years earlier and that the species vanished around 24,000 years ago, earlier than most other megafauna. Climate change, loss of cave sites and competition and hunting by humans are all proposed explanations.