Discovery of the Middle Jurassic Small Theropod Footprints in Eastern Tibet, China

Jurassic continental strata are widely distributed in the Changdu area of eastern Tibet, but very few dinosaur footprints have been reported. Abundant sauropod, ornithopod and theropod footprints preserved in the Wenda site have been found during the recent geological surveys. This is a novel assemblage of the Middle Jurassic dinosaur footprints. These footprint fossils provide a key insight into the members of dinosaur faunas, and the behavior of the trackmakers. Here, the newly discovery small theropod footprints, which are identified as Wildeichnus isp., are discussed. The analysis of two trackways suggest that these two trackmakers (with a hip height of approx. 35 cm, and a body length of approx. 1 m) were moving slowly, with an estimated speed of 0.82 and 0.57 m/s, respectively. It is unusual for small theropods to move so slowly, and the present study supports the view that Wildeichnus had a global distribution, but the trackmaker of Wildeichnus is not interpreted as a juvenile Grallator.