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- Ceratosaurus
- TIME: Late Jurassic
- LOCALITY: North America (Colorado)
- SIZE: 20 ft/6 m long
-
- This is the dinosaur that gave its name to
- the whole infraorder. The name means
- "horned lizard," and refers to the low crest,
- or horn, on its snout. There was also a pair
- of bony ridges above the eyes.The function of
- the horn remains a mystery, although various
- suggestions have been put forward as to its
- use. It could have been used for defense, but
- it seems too small and not well placed for a
- fight. Or it could have been for sexual
- display, with only the males possessing it
- and using it in the ritualistic, head-butting
- battles probably engaged in to decide
- hierarchy among the group.Ceratosaurus was
- evidently an active predator. It had massive
- jaws, armed with sharp, curved teeth. The
- short arms had 4 powerful, clawed fingers and
- the long legs had 3 clawed toes on each foot.
- An unusual feature was a narrow row of bony
- plates running down the center of its back
- and tail giving the appearance of a serrated
- crest. This could have been a device for
- losing heat from the body, similar to the
- back fin of Spinosaurus or the plates of
- Stegosaurus.Footprints thought to be those of
- Ceratosaurus have been preserved in the
- dinosaur-rich rocks of the Morrison Formation
- in the western USA. These ancient trackways
- suggest that these dinosaurs moved in groups,
- and maybe cooperated in packs to bring down
- the larger dinosaurs.
-
- Subject by: Russell Webb
-