Cretaceous saurischian tracksites from southwest Sichuan Province and overview of Late Cretaceous dinosaur track assemblages of China

Abstract

Dinosaur tracks from Upper Cretaceous deposits of Sichuan Province, China have proved of great significance for two reasons: they (1) provide unambiguous evidence of dinosaurs from this epoch in this region, and (2) demonstrate that the track bearing units of the Leidashu Formation are not Paleocene-Eocene in age as previously claimed by some authors. We herein describe five small sites, from the Zhaojue area and the nearby Xide areas. Two sites are dominated by theropod tracks, including one with small tracks of Eubrontes-like morphology, and another with deep tracks revealing long metatarsal impressions, probably indicating a soft substrate. Three sites yield only sauropod tracks. Combined data from these five tracksites document a typical saurischian dominated ichnofauna, and based on present evidence these assemblages are less diverse than those from Lower Cretaceous sites in the region. However a larger sample is necessary to test this suggestion.