National Geographic : 2003 Mar
When McCrea presented his master's thesis, he jokingly You know, two dinosaurs mating. Reptilian passion captured in stone. The professors were not visibly amused. (Continuedfrom page 8) ruled by titanic crea tures, thriving all over the globe from 230 to 65 million years ago, during the Mesozoic era. And the field has charms that the laboratory can't match. The field is the staging ground for that whole Indiana Jones thing, for the type of charismatic, rock-star scientists who hang out in dinosaur graveyards with shovels, picks, plaster, graduate students, and personal documentary film crews. But perhaps the very glamour of dinosaurs has spawned the backlash, the willful retreat to scientific basics by Greg Erickson and research ers like him. Most scientific disciplines aren't caught in the gravity well of public fascination. If you study fossil mollusks, for example, you aren't likely to be asked to become a scientific adviser for a Hollywood blockbuster. No one has snail fever. But dinosaur fans are insatiable for information. The new generation of scientists wants to put constraints on all the hypotheses flying around, and they think that the truth about dinosaurs-and dinosaur behavior won't be uncovered with bones alone. "For 20 years we've done what we call arm waving," says Jack Horner, a legendary bone collector. "We've made hypotheses based on very little evidence. Now we're sitting down, we're saying, 'We've got all these ideas, are they real?'" Horner can arm-wave like a champ, as he will admit. Since 1991 he's been arguing, for 14 NATIONAL GEOGRAPHIC * MARCH 2003 example, that Tyrannosaurus rex, the very emblem of predation, the killer of killers, was actually just a scavenger, an eater of the dead. An overgrown turkey vulture! Those banana size teeth weren't for ripping live flesh, says Horner, they were for crushing the bones of a carcass. This is vintage contrarianism, and Horner so far has failed to persuade many of his peers, who point out that T7rex need not have been one thing or another. Hyenas, for example, are scavengers one day, predators the next. But in any case this is precisely the kind of argument that can't be won by speaking louder than one's opponents. Science requires data. Science requires that ideas be subjected to tests. And paleontology-if the new generation has its way-will be seen as a no-nonsense field, a hard science, in addition to being a thrill ing subject built around the bones of large, scary animals. Shis is where we have the rhino heads Sand the manatee heads," Lawrence Wit mer is saying. "We've got a whole bin of ostrich heads and necks. We've got ducks and geese. Here's a bag of alligator parts." We're in the deep freeze of his laboratory at Ohio University in Athens. Witmer has quite the collection of heads. They belonged to creatures that died, or were killed for some other reason, and were then obtained by Witmer for research.