Information AboutPachycephalosaurus |
| CATEGORIES ABOUT PACHYCEPHALOSAURUS | |
| cretaceous dinosaurs | |
| dinosaurs of north america | |
| jurassic park species | |
| pachycephalosaurs | |
''Pachycephalosaurus'' {Link without Title} is a Dinosaur of the family Pachycephalosauridae , from the Late Cretaceous of North America. (This is in the Ornithischia order.) Its name means "Thick headed reptile". It was a herbivorous creature, which lived in the late Cretaceous period. It is only known from a single skull and a few extremely thick skull roofs. ANATOMY ''Pachycephalosaurus'' was probably bipedal and was the largest of the bone-headed dinosaurs, it is famous for having a large, bony dome atop its skull, up to 25cm (10 inches) thick, which safely cushioned its brain. The dome's rear was edged with bony knobs and short bony spikes were projected upwards from the snout; these suggest that despite their bipedal stance they were not ornithopods but relatives of the Ceratopsian s. From other Pachycephalosauridae it has been estimated that the ''Pachycephalosaurus'' was around the length of a large car, maybe around 4.6m long (15 feet) and had a fairly short, thick neck, short arms, a bulky body, long legs, and a heavy tail, which was likely to have been held rigid by hard bony tendons. Large eye-sockets that faced forward suggest that the animal had sharp eyes capable of binocular vision. LIFESTYLE Scientists once suspected that ''Pachycephalosaurus'' and its dome-headed relatives were the bipedal equivalents of the bighorned sheep of today. It was thought that in the mating season, big males evidently ran at one another, clashing heads to decide which would dominate and mate with a herd of females. It was thought that they used their domed heads for defence against predators. However it is now known that the Pachycephalosaurus' did not use their domes this way. The adult head bones did not stand up to pressure well, and the skulls lacked proper shock absoption. Also, there is no evidence of scars or other damage on fossilized Pachycephalosaurus skulls. See Goodwin, Mark and Horner, John. 2004. Cranial histology of pacycephalosaurs (Ornithischia: Marginocephalia) reveals transitory structures inconsistent with head-butting behavior. Paleobiology 30(2):253-267. for details of Pachycephalosaurus skulls and headbutting. While feeding, a ''Pachycephalosaurus'' herd would have been keenly aware of how close they could safely allowa tyrannosaur to approach before they ran away. DIET Scientists do not yet know what these dinosaurs ate. Having very small, ridged teeth they could not have chewed up tough, fibrous plants as effectively as other dinosaurs of the same time period. It is assumed that 'pachycephalosaurs' lived on a mixed diet of leaves, seeds, fruit and insects. Pachycephalosaurus's sharp, serrated teeth would have been very effective for shredding angiosperm plants. EXTERNAL LINKS |
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