A large mamenchisaurid from the Junggar Basin, Xinjiang, People's Republic of China

Abstract

An articulated neck of a large, mature sauropod, with enormously elongated cervical ribs, was discovered in strata of Late Jurassic age in the eastern Junggar Basin, Xinjiang, People's Republic of China. The animal is estimated to have originally measured 26 m in length, but was lightly proportioned relative to Brachiosaurus and Apatosaurus. Rudimentary spines on the anteriormost cervical vertebrae diagnose a previously undescribed species of Mamenchisaurus. Cranial parts associated with the neck do not support a close relationship with diplodocids. Mamenchisaurs apparently belong to an endemic Jurassic radiation of Asian sauropods.

New Bathonian (Middle Jurassic) sauropod remains from the Valtos Formation, Isle of Skye, Scotland

“…Mamenchisaurus lacks wear facets on the elongated crowns, but does have serrations on the anterior carina (Russell & Zheng 1993). One of the most primitive sauropods from the early Jurassic of China, Gongxianosaurus, has an asymmetric spoon-shaped crown and lacks the lingual ridge and serrations (He et al 1998).…”

A new crocodyliform from the middle Cretaceous Galula Formation, southwestern Tanzania

“…The element (Mal-284; Figure 7D-E) identified as splenial is thin (5 mm wide). A splenial foramen occurs on the anterior half of the element as in Mamenchisaurus (Russell and Zheng 1993). The posterior half of the element is separated into a long, slender ventral ramus and a short, broad dorsal ramus.…”

“…Anteroposterior decrease in tooth size and variability of curvature between anterior and posterior and between upper and lower teeth are features that are also present in Camarasaurus (Osborn and Mook 1921;Carey and Madsen 1972), Nemegtosaurus (Nowinski 1971) and Quaesitosaurus (Kurzanov and Bannikov 1983). In Mamenchisaurus (Russell and Zheng 1993), teeth diminish in size as crowns become more compressed.…”

Dinosaurs from the Early Cretaceous Murtoi Formation in Buryatia, eastern Russia

“…1, 3). However, denticles are also present in Mamenchisaurus (Russell and Zheng 1993). Teeth from Thailand are similar to those of Mamenchisaurus fuxiensis (= Zigongosaurus fuxiensis Hou, Chao, and Chen, 1976) from the Wujiaba locality in the lower part of the Upper Shaximiao Formation of Zigong, China (Haiyan Tong and Hui Ouyang, personal communication 2009).…”