Evaluating combat in ornithischian dinosaurs

Abstract Ornithischia, a diverse clade of herbivorous dinosaurs, has numerous members with structures hypothesized to function in combat. These include the horned ceratopsids, dome‐headed pachycephalosaurs, spike‐thumbed iguanodonts, tail‐clubbed ankylosaurs and spiked stegosaurs, among others. Three main lines of evidence support such inferences: (1) analogy with modern animals; (2) biomechanical analysis and simulation; and (3) paleopathology. The most solid inferences utilize multiple pieces of evidence, although this is hampered by a limited understanding of combat in modern animals.