Table 1. Comparison of quadrate, maxillary, and mandibular rotational movements in Corythosaurus model (Weishampel 1984, figure 20) and Edmontosaurus model (this study). Rotational movements (in degrees) are described for lateral and anterior views of the skull and occurred at the powerstroke phase of the chewing cycle only. Quadrate movements occur at the squamosal articulation. Maxillary movements occur about the lacrimal joint. Rotational movements in anterior view are abduction.