A theropod dinosaur feeding site from the Upper Jurassic of the Junggar Basin, NW China

Direct evidence for theropod feeding behaviour is rare in the fossil record, and mainly limited to bite marks on bones. Here we describe a dinosaur assemblage from the lower part of the early Late Jurassic Qigu Formation at Liuhuanggou Gorge, southern Junggar Basin, NW China, which has yielded fragmentary remains of a large sauropod as well as four teeth of large-sized theropods and one tooth of a small-sized theropod. The sauropod bones show numerous bite marks that can be confidently linked to the large-sized theropod, probably a metriacanthosaurid. The abundance of the theropod bite marks on a single skeleton indicates that the sauropod carcass was probably fed on extensively. Some bones are completely crushed and occur in patches of hundreds of tiny individual fragments indicating that they were trampled repeatedly by large dinosaurs. Both the feeding traces and the trampling suggests that the sauropod carcass was exposed for a substantial amount of time before it was finally buried within the deposits of a well-drained floodplain. The traces and the distinct preservation of the sauropod remains offer valuable insights into the feeding behaviour of large-sized theropods within Late Jurassic continental ecosystems.