Ceratopsia

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Ceratopsia

[‚ser·ə′täp·sē·ə]
(paleontology)
The horned dinosaurs, a suborder of Upper Cretaceous reptiles in the order Ornithischia.

Ceratopsia

 

(horned dinosaurs), a suborder of reptiles of the order Ornithischia. Horned dinosaurs lived during the Late Cretaceous in Central Asia (the most ancient representatives) and in South and North America. They resembled rhinoceroses and had a body length to 6 m. The neck was encircled by a “frill” of proliferated skull bones. The frill served as protection against predators. The majority of ceratopsians had between one and five horns on the head and, sometimes, accessory bony spines along the edges of the frill. The anterior portion of the jaws formed the “bill.” The teeth were arranged in several rows and served for grinding plant substances. The anterior cervical vertebrae, which supported the heavy skull, were usually concresced. The feet were hoofed. Horned dinosaurs lived in the forest steppe and in meadows near water. They were among the last dinosaurs, becoming extinct at the end of the Cretaceous.

References in periodicals archive ?
The evidence provided by the scaling equation for humeral diameter indicates that ceratopsians were complex organisms with a number of powerfully adaptive structures that reduced bending stresses in their limbs, in ways other than a simple increase of the surface area through which stress operated.
The behavioral significance of frill and horn morphology in ceratopsians.
There has been a great deal of controversy in the last 20 years about whether ceratopsian (horned) dinosaurs held their forelimbs in an essentially vertical position and were capable of galloping (Bakker, 1971, 1986; Desmond, 1976), or held their forelimbs in a more horizontal or sprawling position that would preclude galloping (Bennett and Dalzell, 1972; Coombs, 1978; Farlow and Dodson, 1975; Lehman, 1982, 1989).
The assertion that ceratopsian limb bones are so massively shafted that they are evidence of adaptation to stresses engendered by galloping subsumes this relationship between bone diameter and length, and implies that the diameters of ceratopsian limbs are larger than would be expected based on the scaling equation.
Despite the impressive size of the ceratopsian humerus, it does not have as much of a "massive shaft" as it should.
The lower-than-expected diameter values for ceratopsian humeri may indicate the presence of a number of such powerful alternative structural adaptations to stress in ceratopsian limb bones that obviate a full, allometric increase in cross-sectional area of the shaft.
The bigger they are, the harder they fall: implications of ischial curvature in ceratopsian dinosaurs.
History and critical analysis of the ceratopsian dinosaur stance and gait controversy.
Descriptive and cladistic analysis of ceratopsian dinosaur forelimb osteology.
A ceratopsian bone bed from the Aguja Formation (upper Cretaceous) Big Bend National Park, Texas.