【化石】羽毛の生えた大型のドロマエオサウルス科恐竜

A large, short-armed, feathered dromaeosaurid dinosaur - one of the closest extinct relatives of birds - found in the Liaoning Province, northeastern China is described in Scientific Reports this week. Although smaller dromaeosaurids have been found with feathers, the new species is the first reported evidence of feathers in larger, short-armed members of the family. The specimen adds more diversity to the already famous Liaoning feathered dinosaurs from the Early Cretaceous period.

Most Liaoning dromaeosaurids were small animals, around the size of a house cat or medium-sized dog, which had long forelimbs and broad wings covered in feathers. The one reported exception is a single, previously reported specimen called Tianyuraptor, a larger animal that approached two metres in body length and had comparatively shorter forelimbs but did not have any preserved feathers. Thus, whether relatives with this rare body plan may have had feathers has remained an open question.

A new fossil called Zhenyuanlong, described by Junchang Lu and Stephen Brusatte, is only the second reported dromaeosaurid with short arms, and the first of its type to be found with feathers on its arms and tail. Zhenyuanlong is distinct from Tianyuraptor as it is slightly smaller (measuring around 126-165 cm in length) and has proportionally shorter arms, although these forelimbs supported large, feathered wings. Whether these wings served any type of flying capability remains unknown.