An extinct owl (aves: strigidae) from the middle miocene of Patagonia

Abstract

Yarquen dolgopolae gen. et sp. nov. is described from fragmentary fossil bones (humerus and phalanges) found in the Middle Miocene Collón Curá Formation (Río Negro Province, Argentina). Fossil owls in Argentina are limited to occasional fragments as old as the Early Miocene to Late Pleistocene. Here, an extinct species is described. The humerus (MLP 92-V-10-86) is similar in size to that of the Short-eared Owl but differs mainly by the depth and arrangement of the fossa m brachialis, the fossa olecrani is shallow and rimless, the sulcus scapulotricipitalis is shallow, a pneumatic foramen located on a scar proximal to the condylus ventralis, the incisura intercondilaris is narrow and the condylus ventralis is rounded with a conspicuous groove running caudoventrally. The ungual phalanx of digit 1 shows a strongly curved corpus, lateral grooves on both sides, a processus extensorius dorsally directed, a flexor tubercle wide and robust and a crista slightly protruding that separates both cotylae. Aves recovered from the Collón Curá Formation correspond to diurnal hunters (Phorusrhacidae and Falconidae) to which is added this large owl that, like other Strigidae, presumably was nocturnal or crepuscular hunters.