National Geographic : 1999 Nov
showed me the other feathered theropod, Beipiaosaurus inexpectus, one of only a few therizinosaur specimens known. Farmers dis covered the gray bones near the town of Bei piao and discarded them, believing they had no commercial value. Xu and his colleagues chanced upon scraps of the fossil and salvaged the remaining pieces from the site. The young scientist handed me a flat piece of rock about the size of my hand. It bore 01999 UNIVERSALCITYSTUDIOS.COURTESYUNIVERSALSTUDIOSPUBLISHINGRIGHTS. ALL RIGHTSRESERVED(ABOVE);ARTBYPORTIASLOAN Tyrannosaurus FEATHERS FOR T. REX? pink comblike impressions that suggested stiff, narrow feathers. "These filaments might have had hollow cores," he said. This is a key feature, since hollow, hairlike structures char acterize protofeathers-evolutionary inter mediates between reptilian skin and feathers. At seven feet long, Beipiaosaurus is the largest dinosaur yet found with feathers. But why did it have them, since neither this theri zinosaur nor its ancestors ever flew? One explanation is that their feathers did not evolve for flight but for insulation-which gives rise to another question: Were dinosaurs warm blooded? Biologist Mary Schweitzer of Montana State University, who has studied the small fibrous structures on a birdlike creature from Mongolia named Shuvuuia deserti, is helping to answer that question. Her tests show that the fibers are similar, chemically and structurally, to modern feathers. "The only animals living today with body coverings of hair or feathers Obsolete model: Baby T rex in 1997's Lost World: JurassicPark probably would have feathers if the movie were made today. Unnamed oviraptorosaur Beipiaosaurus inexpectus Sinornithosaurusmillenii -- Archaeoraptor liaoningensis A new Mongolian specimen The largest dinosaur found with Though a classic dromaeosaur Preliminary studies show that possesses an early evolutionary feathers measures seven feet tail establishes that it is a this specimen has startling version of a birdlike tailbone. long and bears two-inch-long dinosaur, other skeletal features similarities to both dinosaurs plumage. closely resemble those of birds. and birds.