Objective Recently, a large number of dinosaur footprints have been discovered in the Tuchengzi Formation in Xuanhua District, Hebei Province, which not only provides extremely valuable basic materials for the study and restoration of the paleoecology of the Tuchengzi Formation, especially the paleoecology and paleogeographic environment of the dinosaur fauna, but also shows very important scientific significance and research value. Although many related research results have been published at home and abroad, there are great controversial about the stratigraph depositional sequence, sedimentary environment and chronology of horrizon of dinosaur footprints in the Tuchengzi Formation.

Methods On the basis of detailed field geological investigation, the paper systematically studied and discussed the Tuchengzi Formation where dinosaur footprints were preserved in Lishi County, Xuanhua through stratigraphy, sedimentology and comprehensive analysis.

Results In this study, the Tuchengzi Formation of Lishi County in Xuanhua is divided into four members vertically, and the dinosaur footprints are not developed in the first member as previous people supposed, but in the siltstone and fine sandstone rhythm at the bottom of the forth members, and form two sedimentary cyclic sequences of "shallow lake−braided river−alluvial fan" from bottom to top.

Conclusions Comprehensive evidence, encompassing sedimentary structures and tectonic features, suggests that the dinosaur footprints originated in a sedimentary setting characterized by shallow water or intermittently exposed floodplains of fluvial facies. The zircon U-Pb dating of the tuff overlying the dinosaur footprints within the Tuchengzi Formation in Xuanhua indicates an age range of 155~142 Ma, implying that these footprints likely formed from the early stage of the Late Jurassic to the early stage of the Early Cretaceous.