title: A large, short-armed, winged dromaeosaurid (Dinosauria: Theropoda) from the Early Cretaceous of China and its implications for feather evolution.
abstract: The famous 'feathered dinosaurs' from the Early Cretaceous of Liaoning Province, northeastern China, include several dromaeosaurids, which are among the closest relatives of birds. Most of these are small-bodied taxa with long arms and broad wings comprised of vaned feathers, but a single specimen (the holotype of Tianyuraptor) belongs to a much larger individual with reduced forelimbs, which unfortunately lacks any preserved integument. We describe a new specimen of large-bodied, short-armed Liaoning dromaeosaurid, which we designate as a new genus and species, Zhenyuanlong suni. The integument is well preserved and provides the first evidence of feather morphologies and distribution in a short-armed (and probably non-volant) dromaeosaurid, indicating that these rare and aberrant taxa had large wings consisting of pennaceous feathers on the arms and long pennaceous feathers on the tail very similar to their smaller and longer-armed relatives, but potentially lacked vaned feathers on the legs. Zhenyuanlong adds yet more diversity to the Liaoning dromaeosaurid fauna, helps further reveal a distinct short-armed bauplan among dromaeosaurids, and illuminates previously-unrecognized homoplasy that complicates dromaeosaurid phylogeny and suggests that the Liaoning taxa may not have formed their own clade.
authors.affiliation: Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China; Key Lab of Stratigraphy and Paleontology, Ministry of Land and Resources of China, Beijing 100037, China.
authors.forename: Junchang
authors.initials: J
authors.lastname: Lü
authors.affiliation: School of GeoSciences, University of Edinburgh, Grant Institute, James Hutton Road, Edinburgh EH9 3FE, United Kingdom.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Brusatte
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002681:China; D025061:Dinosaurs / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics; D005241:Feathers; D005580:Fossils; D010802:Phylogeny; D014921:Wings, Animal