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The Behavioral Significance of Frill and Horn Morphology in Ceratopsian Dinosaurs
James O. Farlow and Peter Dodson
Vol. 29, No. 2 (Jun., 1975), pp. 353-361
Published by: Society for the Study of Evolution
Stable URL: http://www.jstor.org/stable/2407222
Page Count: 9
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Ceratopsian dinosaurs show a great diversity of horn and frill shapes. Differences in cranial morphology reflect differences in species-specific courtship and agonistic behavior, as is seen in extant horned ungulates and horned lizards. In the earliest ceratopsians, combat involved swinging a small, sharp nasal horn against the flanks of opponents. In some of these forms display was already somewhat cephalized, with the frill serving as a visual dominance rank symbol. Most later ceratopsians can be characterized as long-frilled or short-frilled forms. In long-frilled forms the display function of the frill was hightened. Combat involved frontal engagement of the horns of opponents and accompanying shoving and wrestling to settle contests. Most short-frilled ceratopsians were rather rhinoceros-like in appearance and probably agonistic behavior. Because an opponent's horn could not be caught with one's own horn, the possibility of injury may have been greater in short-frilled forms. Styracosaurus was a short-frilled ceratopsian that was made visually a long-frilled form by the presence of long spikes on the frill. Triceratops was a short-frilled form in which the mode of combat was somewhat similar to that of long-frilled forms, but where the frill served as a shield against opponents' horns. While courtship and agonistic behavior were not the only factors controlling ceratopsian horn and frill morphology, such factors probably were of great or even paramount importance in both the initial enlargement and subsequent evolution of these structures.
Evolution © 1975 Society for the Study of Evolution