page_title: Dinosaur behavior
section_title: Ceratopsian behavior
hierarchical_section_title: Dinosaur behavior / Ceratopsian behavior
caption_attribution_description: The centrosaurinae ceratopsians drawn to scale, pencil drawing, digital coloring
context_page_description: Dinosaur behavior is difficult for paleontologists to study since much of paleontology is dependent solely on the physical remains of ancient life. However, trace fossils and paleopathology can give insight into dinosaur behavior. Interpretations of dinosaur behavior are generally based on the pose of body fossils and their habitat, computer simulations of their biomechanics, and comparisons with modern animals in similar ecological niches. As such, the current understanding of dinosaur behavior relies on speculation, and will likely remain controversial for the foreseeable future. However, there is general agreement that some behaviors which are common in crocodiles and birds, dinosaurs' closest living relatives, were also common among dinosaurs. Gregarious behavior was common in many dinosaur species. Dinosaurs may have congregated in herds for defense, for migratory purposes, or to provide protection for their young. There is evidence that many types of dinosaurs, including various theropods, sauropods, ankylosaurians, ornithopods, and ceratopsians, formed aggregations of immature individuals.
context_section_description: Parental care is implied by the fossilized remains of a grouping of Psittacosaurus consisting of one adult and 34 juveniles. In this case, the large number of juveniles may be due to communal nesting.
  Fossil deposits dominated large numbers of ceratopsids from individual species suggest that these animals were at least somewhat social. However, the exact nature of ceratopsid social behavior has historically been controversial. In 1997, Lehman argued that the aggregations of many individuals preserved in bonebeds originated as local "infestations" and compared them to similar modern occurrences in crocodiles and tortoises. Other authors, such as Scott D. Sampson, interpret these deposits as the remains of large "socially complex" herds.
  Modern animals with mating signals as prominent as the horns and frills of ceratopsians tend to form these kinds of large, intricate associations. Sampson found in previous work that the centrosaurine ceratopsids did not achieve fully developed mating signals until nearly fully grown. He finds commonality between the slow growth of mating signals in centrosaurines and the extended adolescence of animals whose social structures are ranked hierarchies founded on age-related differences. In these sorts of groups young males are typically sexually mature for several years before actually beginning to breed, when their mating signals are most fully developed. Females, by contrast do not have such an extended adolescence.
  Other researchers who support the idea of ceratopsid herding have speculated that these associations were seasonal.  This hypothesis portrays ceratopsids as living in small groups near the coasts during the rainy season and inland with the onset of the dry season. Support for the idea that ceratopsids formed herds inland comes from the greater abundance of bonebeds in inland deposits than coastal ones. The migration of ceratopsids away from the coasts may have represented a move to their nesting grounds. Many African herding animals engage in this kind of seasonal herding today. Herds would also have afforded some level of protection from the chief predators of ceratopsids, tyrannosaurids.
caption: Centrosaurine ceratopsids did not fully develop their cranial ornamentation until fully grown. Scott Sampson argues that comparing ceratopsids to modern mammals with a similar lifecycle can yield insight into the socioecology of the ancient horned dinosaurs.
exif: {}