A flightless 450-kilogram bird roved Europe some 1.7 million years ago, just as ancestral humans reached the continent.
Scientists have found ancient fossils of giant birds in places such as Madagascar, but it was unclear whether enormous birds ever inhabited Europe. New evidence comes from a femur that Nikita Zelenkov at the Russian Academy of Sciences in Moscow and his colleagues found in a cave near the Black Sea.
Analysis shows that it belongs to the known bird species Pachystruthio dmanisensis, but the bird was much bigger than previously thought. The researchers estimate that Pachystruthio was up to 3.5 metres tall at the shoulder and weighed almost as much as an adult polar bear, which makes it one of the largest known birds — and the only one of such size in the Northern Hemisphere.
Pachystruthio had a thin, long femur, similar to that of modern ostriches, which suggests that it was a good runner. The bird’s fleetness might have helped it to escape from predators including sabretoothed cats, the scientists say.