Upper Jurassic dinosaur tracks from the Tianchihe Formation of Shanxi Province, China: review and new observations

Abstract

ABSTRACT A sauropod track assemblage from a surface in the Upper Jurassic fluvial Tianchihe Formation at the Guanxi site, Shanxi Province, China, is re-documented and analysed in detail, together with a recently discovered new locality situated nearby. In contrast to earlier reports, the former includes four trackways plus isolated tracks (41 tracks in total) instead of five trackways (37 tracks in total) identified earlier, with pes prints reaching more than 60 cm in length. The new site has three pes-manus track pairs belonging to smaller individuals, with pes prints being about 20 cm in length. The absence of larger sized tracks at this locality suggests the possible presence of size-differentiated groups representing juveniles or subadults. Track morphology, heteropody and the medium-wide gauge trackway pattern at both sites support an assignment to the ichnogenus Brontopodus. Trackmakers were eusauropods, possibly mamenchisaurids or more advanced forms such as macronarians. Results of re-investigation allow a new interpretation of trackway orientations and trackmaker behaviour, respectively, as well as a calculation of progression speeds that suggest walking movement.