Labels:text | font | paper | document OCR: A near relative of Diplodocus, Barosaurus ("heavy lizard") was an immensely long sauropod ("lizard-footed" dinosaur). Both had a bulky body that stood highest at the hips. Their hindlimb bones appear identical, and other bones suggest that Barosaurus' skull (which has not yet been discovered) was long and sloping like that of Diplodocus; but their neck and tail proportions were different. Barosaurus' tail was relatively short, and although the tail tip remains undiscovered, scientists believe that it probably ended in a flexible whiplash. This was balanced by an extremely elongated neck that projected about 9 m (30 ft) beyond its shoulders, making Barosaurus longer than almost any other North American dinosaur. ENORMOUS HEART Barosaurus' long neck seems designed for feeding at high elevations, like a giraffe's. Some researchers have calculated that pumping blood up to the brain demanded an amazingly large 1.4 tonnne (11/2-ton) heart. But the bigger a heart, the slower it beats. In 1992, scientists at Columbia University argued that a 1.4 tonne (11/2-ton) heart would pump so slowly that blood forced up the neck by one heartbeat would pour back down before the next. They suggested instead that Barosaurus had eight hearts - two major hearts in the chest and three pairs of lesser hearts spaced out along the neck; each heart was only big enough to pump blood to the next, but all worked as a team to drive blood to the brain. EARLY DEATH The Columbia University scientists also theorized that the resultant high blood pressure made this dinosaur prone to arterial disease and early death from heart attack or stroke. Others thought that Barosaurus managed with one moderately large heart aided by arterial valves in the neck to stop blood falling back. Many now believe it never raised its neck very high at all.
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