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We report five new dinosaur track sites in Chaya County, about 120 km southeast of Changdu City. The track assemblages are dominated by sauropods (45 tracks), which have been identified tentatively as cf. Brontopodus. Also present are two thyreophoran trackways consisting of 13 tracks that show strong similarities with the ichnogenus Deltapodus, the potential trackmakers of which were probably stegosaurids. The sauropod tracks from the Chaya region are dominated by large tracks with different affinities if compared to those of the Changdu area. The isolated sauropod tracks from Changdu and Chaya regions show similar morphological patterns, but those from the Chaya region lack large scale tracks. This paper compares and discusses the known ichno and body fossil records of sauropods, theropods, and ornithischians from the Middle Jurassic of Yunnan, Sichuan, and eastern Tibet and their importance for our understanding of dinosaur faunas from this region. The absence of basal neornithischian records in the Yunnan and Changdu regions is likely a preservational bias but also an ecological pecularity cannot be completely excluded. The palaeogeographic position of the four sampled skeleton and track sites suggests the possible existence of a corridor through which faunal exchanges were taking place throughout the Jurassic. [ABSTRACT FROM AUTHOR]

Type specimens of the sauropod ichnotaxon Chuxiongpus changlingensis, which was later reassigned to Brontopodus changlingensis, as well as the theropod ichnotaxon Yunnanpus huangcaoensis, both from the Cretaceous Jiangdihe Formation of Yunnan Province, are redescribed in order to document their morphological features. Both, but particularly Y. huangcaoensis, which is considered now a nomen dubium, were originally based on poorly preserved material. Nevertheless, the specimens document a saurischian dominated biota that existed during the deposition of the Jiangdihe Formation from which no skeletal remains are known. B. changlingensis trackways were left by small sauropods that show consistent partial or complete overprint of the manus by the pes. This pattern makes it difficult to calculate manus length, and heteropody can be only estimated. [ABSTRACT FROM AUTHOR]

The new ichnospecies,Shenmuichnus wangiichnosp. nov., is the first evidence for the presence of large ornithischians in the Early Jurassic of Yunnan Province, whereas the known skeletal record documents small species only. Until nowShenmuichnuswas known from a single locality in Shaanxi Province by the ichnospeciesShenmuichnus youngteilhardorum. Compared with the latter,Shenmuichnus wangiis larger and shows a different trackway configuration, particularly in the relative position of manus and pes imprints. Palecologically, the occurrence ofShenmuichnus wangiin a red bed facies indicates the preference of distinctive environments of trackmakers of both ichnospecies, questioning former hypotheses of exclusivity of ornithischians in more humid climates. By abundance both skeletons and footprints of ornithischians suggest their role as a minor component in Early Jurassic saurischian dominated dinosaur faunas in this region. [ABSTRACT FROM AUTHOR]