title: A new raptorial dinosaur with exceptionally long feathering provides insights into dromaeosaurid flight performance.
abstract: Microraptorines are a group of predatory dromaeosaurid theropod dinosaurs with aerodynamic capacity. These close relatives of birds are essential for testing hypotheses explaining the origin and early evolution of avian flight. Here we describe a new 'four-winged' microraptorine, Changyuraptor yangi, from the Early Cretaceous Jehol Biota of China. With tail feathers that are nearly 30 cm long, roughly 30% the length of the skeleton, the new fossil possesses the longest known feathers for any non-avian dinosaur. Furthermore, it is the largest theropod with long, pennaceous feathers attached to the lower hind limbs (that is, 'hindwings'). The lengthy feathered tail of the new fossil provides insight into the flight performance of microraptorines and how they may have maintained aerial competency at larger body sizes. We demonstrate how the low-aspect-ratio tail of the new fossil would have acted as a pitch control structure reducing descent speed and thus playing a key role in landing.
authors.affiliation: Paleontological Center, Bohai University, 19 Keji Road, New Shongshan District, Jinzhou, Liaoning Province 121013, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Han
authors.affiliation: Dinosaur Institute, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007, USA.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Chiappe
authors.affiliation: 1] Paleontological Center, Bohai University, 19 Keji Road, New Shongshan District, Jinzhou, Liaoning Province 121013, China [2] Institute of Geology, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, Beijing 100037, China.
authors.forename: Shu-An
authors.initials: SA
authors.lastname: Ji
authors.affiliation: University of Southern California, Health Sciences Campus, BMT 403, Mail Code 9112, Los Angeles, California 90089, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Habib
authors.affiliation: Health Science Center, T8 (040), Department of Anatomical Sciences, School of Medicine, Stony Brook University, Stony Brook, New York 11794, USA.
authors.forename: Alan H
authors.initials: AH
authors.lastname: Turner
authors.affiliation: Department of Biological Sciences, University of Cape Town, Private Bag X3, Rhodes Gift 7701, South Africa.
authors.forename: Anusuya
authors.initials: A
authors.lastname: Chinsamy
authors.affiliation: Paleontological Center, Bohai University, 19 Keji Road, New Shongshan District, Jinzhou, Liaoning Province 121013, China.
authors.forename: Xueling
authors.initials: X
authors.lastname: Liu
authors.affiliation: Paleontological Center, Bohai University, 19 Keji Road, New Shongshan District, Jinzhou, Liaoning Province 121013, China.
authors.forename: Lizhuo
authors.initials: L
authors.lastname: Han
mesh_terms: D000818:Animals; D025061:Dinosaurs / Q000502:physiology*; D005241:Feathers / Q000502:physiology; D005426:Flight, Animal / Q000502:physiology*; D005580:Fossils