Saturday, May 2, 2009

evolutionary link

On April 25, 2001, the scientific journal Nature presented a report by paleontologists Mark Norell and Ji Qiang regarding what they claimed as proof of an evolutionary link between dinosaurs and birds. The subject of their report was a 135-million-year-old fossil that was discovered in China a year earlier, and that offered evidence of what Norell and Ji believed to be feathers. The scientific community was not unanimous in concurring, but the ranks of dinosaur-bird theory adherents continued to grow.
In spring 2000, farmers in China's Liaoning Province--well known for its fossil riches--made a remarkable discovery in an ancient lakebed. There, covered in volcanic ash, which was about 125 million to 147 million years old, were the remains that were later identified as belonging to a member of the dromaeosaur group. Related to the Tyrannosaurus Rex and Velociraptor, the dromaeosaur lived some 135 million years ago, but was much less imposing than its fearsome cousins. Measuring three feet from head to tail, it was apparently covered in down. Investigating the remains, Norell, of the American Museum of Natural History, and Ji, of the Chinese Academy of Geological Sciences, believed that they had found physical proof of a link between dinosaurs and birds. The down, they maintained, was evidence that the dromaeosaur had feathers.

Yet though a growing number of scientists favor the idea that birds and dinosaurs share an evolutionary heritage, there is still a vocal opposition to this theory, and the Liaoning find elicited considerable controversy among detractors. Ornithologist Storrs Olson at the Smithsonian Institution National Museum of Natural History, for instance, professed to be "convinced that there were no feathers on the beast." Olson, who with others examined the fossil in Beijing in June 2000, explained that "There was fuzz on the wings and tail, which is exactly where you should see feathers the best developed, but they just [aren't] there."

Norell, for his part, maintained that the fossil, with its intact body covering, "clearly shows the typical herring-bone pattern of feathers in parallel lines branching along the backs of shafts." Anyone who could not see evidence of feathers in the fossil of the dromaeosaur, which was flightless, was "simply refusing to give up their old beliefs." According to Ji, the dromaeosaur's inability to fly simply supported the theory that feathers probably developed first for warmth rather than for flight. The appearance of the Liaoning dromaeosaur some 10 million years later than the first true bird, the Archaeopteryx, only highlights the fact that evolution is not an orderly progression, Norell stated.


Chiang, Mona. "Dino-mite Discoveries." Science World, September 3, 2001, pp. 4-5.

Hostetler, A. J. "Experts: First Feathers Weren't for the Birds." Richmond Times-Dispatch, April 27, 2001, p. A2.

Loohauis, Jackie. "A Star Is Hatched." Milwaukee Journal Sentinel, November 23, 2002, p. 6B.

Perlman, David. "Wingless Theropod Gives More Clues." San Francisco Chronicle, April 26, 2001, p. A5.

Wilford, John Noble. "A Feathery Theory Takes Wing." New York Times, April 29, 2001, p. 2.

Source Citation: "Feathered Dinosaur Fossil Provides Possible Evidence of an Evolutionary Link Between Dinosaurs and Birds, April 25, 2001." Historic World Events. Gale, 2004. Reproduced in History Resource Center. Farmington Hills, MI: Gale.


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Len Wilson

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