Hadrosaur (Parasaurolophus)

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The hadrosaurs or duckbills are herbivorous ornithischian (plant-eating, bird-hipped) dinosaurs characterized by formidible dental "batteries" containing hundreds of interlocking crushing teeth in upper and lower jaws and having broader and more elongate bill-like snouts than other ornithischians. Hadrosaurs have relatively long fore-limbs with hoof-like terminations on the forefeet. Parasaurolophus, depicted here, is further distinguished by the presence of extended nasal cavities above the head. These animals are extremely abundant in some fossil deposits. It is thought that they may have moved in herds, much as sheep do today. Although this point is still controversial, it is apparent that Hadrosaurs could walk upright, and probably on "all fours" as well. Just which method was preferred awaits further study, but many trackways thought to have been formed by hadrosaurs show only rear foot impressions.

Click here to see a Hadrosaurus in action (avi format 2.7 meg),