A Giant Early Pleistocene Bird from Eastern Europe: Unexpected Component of Terrestrial Faunas at the Time of Early Homo Arrival

Giant birds, comparable in size to elephant birds and moa, have never been reported from Europe. Here, we describe a femur from the lower Pleistocene of the north Black Sea area (Crimea) that is referred to Pachystruthio dmanisensis, comb. nov., a giant bird with an estimated body mass of about 450 kg. This value makes this extinct bird one of the largest known avians (comparable to Aepyornis maximus) and the only bird of such giant size in Europe and the Northern Hemisphere in general. In contrast to very large insular birds, Pachystruthio dmanisensis was a good runner, which may be explained by its coexistence with large carnivoran mammals. Pachystruthio dmanisensis and associated assemblage of fossil mammals are shared with the Dmanisi locality in Georgia (∼1.8–1.7 Ma); thus, this giant bird was likely a typical component of eastern European faunas at the time of early hominin arrival. We suggest that Pachystruthio dmanisensis, 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.