Together, this evidence of gregarious behaviors suggests that ceratopsians
developed complex social behaviors long before they possessed extreme cranial ornamentations, says Barrett.
One piece of evidence claimed by the proponents of galloping ceratopsians is that their "massive shafted" limb bones are prima facie evidence of cursoriality (Bakker, 1980).
Humeral length and minimum diameter values were recorded for 10 type specimens representing 10 genera of ceratopsians, from both the families Ceratopsidae and Protoceratopsidae (Table 1).
The use of skull length as a size indicator is complicated in ceratopsians by the presence of a large frill extending the posterior margin of the skull.
If the question of ceratopsian galloping could be resolved by the dimensions of humeral diameter, the results would indicate that ceratopsians did not gallop; the dimensions of the humeral shaft diameter provide absolutely no evidence of adaptation to increased stresses imposed by galloping.
Reconstruction of this external force environment and consequent determination of whether or not ceratopsians galloped requires more sophisticated comparative methods or paleobiomechanics or both (Adams, 1991c).
Among the last dinosaurs to survive were Montana's and Alberta's hadrosaurs and ceratopsians, the latter so common that paleontologist Robert Bakker of the University of Colorado calls them "Cretaceous cockroaches.
They've found more than 300 dinosaurs from 35 species, duck-billed hadrosaurs to horned ceratopsians.
Liaoceratops] shows that the evolution of ceratopsians
is more complicated than we'd thought," says Catherine A.
Johnson says that Torosaurs, Triceratops and probably all ceratopsian
dinosaurs had sprawling lizard-like forelimbs after all, and therefore could not gallop.
And among some 10,000 bones I finally discovered four other specimens that could be related to ceratopsians
The sizes and shapes of crystals from the fossil teeth suggest that the ceratopsian
dinosaurs, relatives of Triceratops, may have eaten a high proportion of tough-leafed cycads, whereas the hadrosaurs, or duck-billed dinosaurs, probably favored ferns.