DOI: 10.1127/0077-7749/2007/0243-0113 0077-7749/07/0243-0113 $ 1.50 ©2007 E. Schweizerbart’sche Verlagsbuchhandlung, D-70176 Stuttgart N. Jb. Geol. Paläont. Abh. 2007, vol. 243/1, p. 113 – 118, Stuttgart, January 2007, published online 2007 The first evidence of a stegosaur (Dinosauria, Ornithischia) from the Jurassic of Xinjiang/China Oliver Wings, Hans-Ulrich Pfretzschner, and Michael W. Maisch, Tübingen With 1 figure WINGS, O., PFRETZSCHNER, H.-U. & MAISCH, M. W. (2007): The first evidence of a stegosaur (Dinosauria, Ornithischia) from the Jurassic of Xinjiang /China. – N. Jb. Geol. Paläont., Abh., 243: 113 –118; Stuttgart. Abstract: A well preserved dorsal vertebra of a stegosaur is described from the Oxfordian Qigu Formation of the Junggar Basin, northwestern China. This is the first evidence for thyreophoran dinosaurs in this Formation. Previously, stegosaurs have only been recorded from the Lower Creta- ceous Tugulu Group of this region. Although the generic identity of the specimen is indeterminate, the find provides confirmation for the presence of stegosaurs in the Jurassic of the Xinjiang Uygur Autonomous Region. Key words: Dinosauria; Stegosauria; vertebra; Jurassic; Qigu Formation; Junggar Basin; China. 1. Introduction From 1999 to 2002, members of a Sino-German co- operative project on the Mesozoic stratigraphy and paleontology of the Junggar Basin successfully prospected sediments of the Qigu Formation for verte- brate fossils. The Qigu Formation is a succession of redbeds, usually several hundred meters in thickness, which outcrops along the northern margins of the Tianshan Mountain range. Its age is generally con- sidered to be Oxfordian (lower Upper Jurassic) (EBERTH et al. 2001). Confusingly, similar redbeds in the Turpan Basin, southeast of the Junggar Basin, are also known as Qigu Formation by Chinese scholars (e. g., SHAO et al. 1999), and Upper Jurassic redbeds in the Northern and Eastern parts of the Junggar Basin, which are presumably coeval to the Qigu Formation of the southern part of the latter, are known as Shishugou Formation (e.g., EBERTH et al. 2001). The Shishugou Formation has long been known for its rich fossil content, including well preserved fossil plants and numerous vertebrates (DONG 1992; W ANG et al. 2000). The Qigu Formation, to the contrary, has only yielded a small number of fossils until recently. DONG (2001) noted some dinosaur fossils from the Qigu Formation of the Turpan Basin, which were never described in detail. The specimens of Xin- jiangchelys “latimarginalis” (see MATZKE et al. 2004 for a taxonomic discussion) described by PENG & BRINKMAN (1993) from the “Qigu-Formation” of Pingfengshan in the Eastern Junggar Basin are pro- bably more correctly attributed to the Shishugou Formation. The first substantial fossil vertebrate finds from the Qigu Formation were noted by MAISCH et al. (2001, 2003, 2004), and included xinjiangchelyid turtles, fragments of sauropod dinosaurs and temnospondyl amphibians. The best preserved xinjiangchelyid,