Some observations on trackway evidence for gregarious behavior among small bipedal dinosaurs

Although trackway evidence for social behavior (herding or gregariousness) has been demonstrated for large, mainly quadrupedal dinosaurs, until recently footprint evidence for herding among small bipedal dinosaurs has been sparse. Recent reports now increase the number of sites suggestive of social behavior to nine, found in strata of Early Jurassic through mid-Cretaceous age in Europe, North America and East Asia. Present evidence suggests that small gregarious dinosaurian bipeds included both theropod and ornithopod species.