First discovery of large-bodied dromaeosaurid fossil materials (Dinosauria: Theropoda) from the Upper Cretaceous Quantou Formation, Songliao Basin, Northeast China

This paper reports the first discovery of large-bodied dromaeosaurid fossil materials (Dinosauria: Theropoda) from the lower Upper Cretaceous Quantou Formation, in Changchun area, Jilin Province. The specimens include a manual ungual and a pedal penultimate phalanx. The manual ungual is the larger of the two and laterally flattened, curved and sickle-shaped from the middle to the distal end; the pedal penultimate phalanx is strongly constricted centrally with the subcircular fossae on both sides of the trochlea located in the upper part of the geometric center of the articular arc. The available evidence indicates that these specimens likely belong to an eudromaeosaur. This new discovery provides important reference materials for studies of dromaeosaurid evolution and distribution, as well as a deeper understanding of the paleocommunity and diversity of northeast Asia during the Cretaceous Period.(c) 2023 Elsevier Ltd. All rights reserved.