Labels:text | font | paper | letter | document OCR: Tuojiangosaurus ("Tuo River lizard") is the best-known plated dinosaur from southern China, where a group of plated dinosaurs known as stegosaurs may have evolved before spreading to other continents. It was longer but lighter than today's heaviest rhinoceros and at the hips stood taller than a human. It had a typical stegosaur's small, low head with toothless beak and small cheek teeth, an arched back, a bulky body, a heavy tail, and pillarlike limbs. Neck, back, and tail supported up to 15 pairs of pointed, vertical plates; rounded plates on the neck gave way to tall ones along the back. Two pairs of spikes stuck out from the tail-tip, and each shoulder may have borne a platelike spine. PLACID PLANT-EATER Tuojiangosaurus plodded along river banks, browsing on the ferns and cycads (palmlike tropical plants) that sprouted thickly in the rich river valley soil. Head slung low, the dinosaur cropped mouthfuls of leaves with its horny beak, stuffed them in its cheeks, chewed them between its small, ridged cheek teeth, and swallowed the pulp for digestion in its roomy gut. Tuojiangosaurus would have spent most of its waking life just eating, swallowing, and digesting leaves. Life was usually placid for this and other herbivores (plant-eaters) whose fossils now lie in the Shangshaximiao Formation of southern China: Mamenchisaurus and Omeisaurus (these were vast, long-necked dinosaurs); the small, primitive ornithischian ("bird-hipped" dinosaur) Gongbusaurus; and two more plated dinosaurs - Chialingosaurus and Chungkingosaurus. DISTINCTIVE SPINES When several species of stegosaurs lived closely together, distinctive plates or spines probably served as recognition signals. Occasionally, a Tuojiangosaurus male would have squared off against a rival or met a large, aggressive theropod ("beast-footed" dinosaur). Only its spikes, plates, and hide could save this slow-moving, four-legged dinosaur from the fangs and claws of predators.
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