title: Dinosaur evolution. A Jurassic ornithischian dinosaur from Siberia with both feathers and scales.
abstract: Middle Jurassic to Early Cretaceous deposits from northeastern China have yielded varied theropod dinosaurs bearing feathers. Filamentous integumentary structures have also been described in ornithischian dinosaurs, but whether these filaments can be regarded as part of the evolutionary lineage toward feathers remains controversial. Here we describe a new basal neornithischian dinosaur from the Jurassic of Siberia with small scales around the distal hindlimb, larger imbricated scales around the tail, monofilaments around the head and the thorax, and more complex featherlike structures around the humerus, the femur, and the tibia. The discovery of these branched integumentary structures outside theropods suggests that featherlike structures coexisted with scales and were potentially widespread among the entire dinosaur clade; feathers may thus have been present in the earliest dinosaurs.
authors: Directorate 'Earth and History of Life,' Royal Belgian Institute of Natural Sciences, Rue Vautier 29, B-1000 Brussels, Belgium. pascal.godefroit@naturalsciences.be.
authors: Pascal
authors: P
authors: Godefroit
authors: Institute of Natural Resources, Ecology and Cryology, 26 Butin Street, 672 014 Chita, Russia.
authors: Sofia M
authors: SM
authors: Sinitsa
authors: UJF-CNRS FRE 3405, AGIM, Université Joseph Fourier, Site Santé, 38 706 La Tronche, France.
authors: Danielle
authors: D
authors: Dhouailly
authors: Institute of Geology and Nature Management, FEB RAS, 1 Relochny Street 675 000, Blagoveschensk, Russia.
authors: Yuri L
authors: YL
authors: Bolotsky
authors: Institute of the Earth Crust, SB RAS, 128 Lermontov Street, Irkutsk, 664 033 Irkutsk, Russia.
authors: Alexander V
authors: AV
authors: Sizov
authors: School of Biological, Earth and Environmental Science, University College Cork, Cork, Ireland. School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK.
authors: Maria E
authors: ME
authors: McNamara
authors: School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK.
authors: Michael J
authors: MJ
authors: Benton
authors: Directorate 'Earth and History of Life,' Royal Belgian Institute of Natural Sciences, Rue Vautier 29, B-1000 Brussels, Belgium.
authors: Paul
authors: P
authors: Spagna
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001842:Bone and Bones / Q000033:anatomy & histology; D025061:Dinosaurs / Q000033:anatomy & histology*; D004817:Epidermis / Q000033:anatomy & histology*; D005241:Feathers / Q000033:anatomy & histology*; D006614:Hindlimb / Q000033:anatomy & histology; D012800:Siberia