A giant ostrich-like bird that lived about two million years ago (Pleistocene epoch) has been identified from a fossilized femur found in the Crimean Peninsula, Ukraine.
Named Pachystruthio dmanisensis, the ancient bird was at least 11.5 feet (3.5 m) tall and had an estimated body mass of about 450 kg.
These values make it one of the largest known birds — comparable to the elephant bird Aepyornis maximus — and the only bird of such giant size in Europe and the Northern Hemisphere in general.
In contrast to very large birds from Madagascar, New Zealand and Australia, Pachystruthio dmanisensis was a good runner, which may be explained by its co-existence with large carnivorous mammals.
“Its femur is comparable to modern ostriches as well as smaller species of moa and terror birds. Speed may have been essential to the bird’s survival,” said Dr. Nikita Zelenkov from the Borissiak Paleontological Institute and colleagues.
“Alongside its bones, we found fossils of highly-specialized, massive carnivores from the Ice Age. They included giant cheetah, giant hyenas and saber-toothed cats, which were able to prey on mammoths.”
The nearly complete left femur of Pachystruthio dmanisensis came from the recently-discovered Taurida karst cave in the Belogorsk region, the Crimean Peninsula.
“When I first felt the weight of the bird whose thigh bone I was holding in my hand, I thought it must be a Malagasy elephant bird fossil because no birds of this size have ever been reported from Europe. However, the structure of the bone unexpectedly told a different story,” Dr. Zelenkov said.
“We don’t have enough data yet to say whether it was most closely related to ostriches or to other birds, but we estimate it weighed about 450 kg. This formidable weight is nearly double the largest moa, three times the largest living bird, the common ostrich, and nearly as much as an adult polar bear.”
The paleontologists also found the remains of Pachystruthio dmanisensis and a similar range of fossil mammals at the site of Dmanisi in Georgia.
“Pachystruthio dmanisensis was likely a typical component of eastern European faunas at the time of early hominin arrival,” they said.
“We suggest that this giant bird, together with early Homo and a variety of mammals, reached the northern Black Sea region via the southern Caucasus and Anatolia, because the older (Pliocene) finds of this fauna are known from Georgia and Turkey.”
A paper describing the discovery was published in the Journal of Vertebrate Paleontology.
Nikita V. Zelenkov et al. A giant early Pleistocene bird from eastern Europe: unexpected component of terrestrial faunas at the time of early Homo arrival. Journal of Vertebrate Paleontology, published online June 26, 2019; doi: 10.1080/02724634.2019.1605521