Pachycephalosauria

Goyocephale

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Micropachycephalosaurus

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Homalocephaloidea

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   Homalocephale

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   Pachycephalosauridae

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Pachycephalosauria (Greek for "thick headed lizards") is a group of ornithischian dinosaurs which evolved during the Cretaceous period in what is now North America and Asia. They were all bipedal herbivorous animals with thick skulls; in some species the skull roof is domed and several inches thick. The skull may be surrounded by hornlets (for instance, Pachycephalosaurus) or spikes(Stygimoloch).

Related Topics:
Ornithischian - Dinosaurs - Cretaceous - North America - Asia - Bipedal - Herbivorous - Pachycephalosaurus - Stygimoloch

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The function of the thickened skull roof has been heavily debated. It has frequently been suggested that individuals may have rammed each other head-on, as in mountain goats and musk oxen, however the rounded shape of the skull might tend to result in glancing blows which would damage the neck. Other possibilities include flank-butting (a behavior seen in giraffes) or perhaps defense against predators.

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Species include Pachycephalosaurus, Stegoceras Stygimoloch, Prenocephale, and perhaps Yaverlandia. Majungatholus, once thought to be a pachycephalosaur, is now recognized as an abelisaurid theropod.

Related Topics:
Pachycephalosaurus - Stegoceras - Stygimoloch - Prenocephale - Yaverlandia - Majungatholus - Abelisaurid - Theropod

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