Key words: Dinosauria, Ornithomimosauria, taphonomy, herding, sociality, miring, drought, Cretaceous.

David J. Varricchio [djv@montana.edu], Earth Sciences, Montana State University, Bozeman, MT 59717, USA; Paul C. Sereno [dinosaur@uchicago.edu], Department of Organismal Biology and Anatomy, 1027 E. 57th Street, University of Chicago, Chicago, IL 60637, USA; Zhao Xi-jin [zhaolu54@263.net], Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, PRC; Tan Lin [firsttan@sina.com], Long Hao Geologic and Paleontological Research Center, Department of Land Resources, Hohhot, Nei Mongol 010010, PRC; Jeffrey A. Wilson [wilsonja@umich.edu], Museum of Paleontology and Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109, USA; Gabrielle H. Lyon [glyon@projectexploration.org], Project Exploration, 950 East 61st Street, Chicago, IL 60637, USA.