In Depth
Along with Sinornithomimus, Shenzhousaurus is one of the few ornithomimosaurs that are known to have had gastroliths inside their stomachs. This has led to the suggestion that Shenzhousaurus had a greater leaning towards a herbivorous diet since gastroliths are usually associated with herbivorous animals. However it is not unknown for some predatory animals to have them, including the theropod dinosaur Lourinhanosaurus.
The presence of teeth in the lower jaw also confirms the placement of Shenzhousaurus as a basal ornithomimosaur since later forms would just have a toothless keratinous beak.
Further Reading
– An Early Ostrich Dinosaur and Implications for Ornithomimosaur Phylogeny. – American Museum Novitates. Q. Ji, M. Norell, P. J. Makovicky, K. Gao, S. Ji & C. Yuan – 2003.