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National Geographic : 1993 Jan
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Belayed for dear life in Dinosaur Provincial Park, university student Hans Larsson picks at a rhino-like Centrosaurus. Getting fossils out of the ground is the easy part; cleaning and study take years. Wade Miller, director of Brigham Young University's Earth Science Museum in Provo, Utah, checks on a hundred tons of unexamined fossils stored under the football stadium. social behaviors as herding and parental care. Even better news is that the great beasts of our fantasies are still alive. In the past decade most experts have concurred that, anatomi cally, birds belong on the dinosaur family tree. As Kevin Padian of the University of Cali fornia at Berkeley puts it: "Dinosaurs haven't gone extinct. You have a dinosaur bath in your backyard, roast dinosaur at Thanksgiving, and eat dinosaur nuggets at McDonald's." The name dinosaur was first used in print in 1842 by the English anatomist Sir Richard Owen, when it became clear that newfound fossils were from an unrecognized animal group. Owen combined two Greek words deinos, or "terrible," and sauros, or "liz ard," to describe the remarkable creatures. We know today that dinosaurs trod the earth for 165 million years, from about 230 million to 65 million years ago. Scientists count some 350 known species, half described in just the past 20 years. But they believe this repre sents only a fraction of the species that existed. All probably evolved from a scurrying, bipedal, pheasant-size reptile. Back in Chicago, Sereno's analysis of his new dinosaur's skeleton convinces him it is indeed more primitive than Herrerasaurus.It lacks a flexible jaw that let Herrerasaurusand later carnivores snag and trap struggling prey. Thus Sereno believes this new creature is the closest fossil we have to the first dinosaur. "I call it 'Eoraptor,' " he says. "Eos was the Greek goddess of dawn. Raptor means thief. It was a light-bodied little rascal. And it may have been a thief, dashing in to grab scraps of someone else's kill." Moreover, Sereno says, the new dinosaur helps determine when the dinosaur family tree branched. Paleontologists have long recog nized two major groups of dinosaurs-the saurischians, which had lizard-like hip struc tures, and the ornithischians, whose hips resembled those of birds. Scientists still don't understand how that different hip structure affected their locomotion. The two groups, nevertheless, evolved along distinct paths. The saurischian branch would include many of the most famous dinosaurs: for instance, the sauropods-a grand group of National Geographic,January 1993
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