Buteo spassovi sp. n. - a Late Miocene Buzzard (Accipitridae, Aves) from Bulgaria

Abstract

The tеnth fossil species of the genus Buteo, second of W Palearctic, is described by an almost complete left tibiotarsus from the town of Hadzhidimovo (former Blagoevgrad District, Sofia Region), dated MN zone 11-12. Both sites of g. Buteo in W Palearctic (Grive-Saint-Alban in SE France and Hadzidimovo in SW Bulgaria) mark the S-European distribution of Buzzards (g. Buteo) during the Miocene. Diagnosis: A fossil Late Miocene species of g. Buteo, differing from modern B. buteo, B. rufinus and B. lagopus by the sharper proximal edge of pons supratendineus, narrower sulcus extensorius, almost twice larger tuberositas retinaculi m. fibularis, better developed linea intermuscularis on the cranial surface of diaphysis, blunter (without a tip) distal end of symphisis tibio-fibularis, and widther distal epiphysis, settled widther apart edges of sulcus tendineus on the lateral side of distal epiphysis.