Long-Held Dinosaur Theory Is for the Birds, Study Says

New research shows that birds lack the embryonic thumb that dinosaurs had, suggesting that it is “almost impossible” for the species to be closely related, scientists say.

Researchers at the University of North Carolina, Chapel Hill, made the discovery with a microscopic examination of stages of development in the embryos of birds.

“We consider this to be unequivocal evidence that birds” did not evolve directly from dinosaurs, said Alan Feduccia, chairman of biology at the school and co-author of a study published today in the journal Science. He said the finding is only one piece of a growing body of evidence that disputes the long-held dinosaurs-to-birds theory.

But the North Carolina findings are dismissed by scientists at the American Museum of Natural History in New York, where the theory is part of a $30-million renovation’s two dinosaur halls.

Mark Norell, a museum scientist, said: “No one feature, such as the thumb, can sway things one way or the other.”

Other researchers, however, are less certain.

“The North Carolina work is very, very credible evidence,” said John A. Ruben of Oregon State University in Corvallis. “The idea that birds evolved from dinosaurs is definitely in trouble.”