Fossil backs theory linking dinosaurs to birds

Deep inside the single leg bone of an 80-million-year-old duck-billed dinosaur, scientists have found a hoard of proteins and blood cells providing the first clear biochemical evidence that dinosaurs are indeed the ancestors of modern birds - linked by evolution.

Until now those links had been based mainly on physical evidence - on feathers from dinosaur fossils, on their fossil eggs, on their fossilized birdlike nestlings and on the close resemblance of dinosaurs and birds like the famed "flying dinosaur" called archaeopteryx.

Now the same team of scientists, which found similar biological material in a 68-million-year-old Tyrannosaurus rex two years ago and immediately faced indignant challenges from many other researchers, has found striking confirmation in the details of their newest discovery.

The scientists say that the biological material they analyzed in their new study shows the strongest chemical relationship yet with similar bone and blood cells and proteins of two modern bird species - ostriches and chickens.

UC Berkeley paleontologist Kevin Padian, one of the world's leading dinosaur experts, called the new report "extremely important" - even amazing - not only because the techniques that extracted intact tissues like blood cells were so convincing but also because they will enable scientists to study dinosaur evolution as never before.

The report appears in this week's issue of the journal Science.

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