13 October 2005News.scotsman.com / Press Association
A 90 million-year-old dinosaur with striking bird-like features may force scientists to re-write part of the family tree of the extinct reptiles.
The creature from Argentina is the earliest known dromaeosaur - a group of predator dinosaurs which includes Velociraptor, one of the stars of the movie Jurassic Park. But it looked nothing like the dinosaurs depicted in Stephen Spielberg's film.
Buitreraptor gonzalezorum had a huge hollow wishbone, long wing-like forelimbs, a bird-like pelvis and probably sported short feathers.
About the size of a very large chicken, it had a long neck and tail and a peculiar thin, beak-like snout lined with small and widely spaced teeth. Its teeth lacked the usual serrations along the edges found in other carnivorous dinosaurs that stood on two legs.
A reconstruction of Buitreraptor shows that it was a fast runner and adept at grasping prey with its long arms.
The discovery of an almost complete fossil skeleton at La Buitrera in Neuguen province in Patagonia has caused a stir among palaeontologists.
It dates from before the break-up of an ancient super-landmass to form the northern and southern hemisphere continents of Laurasia and Gondwana.
Scientists now think dromaeosaurs in the separated continents took different evolutionary paths. That may have led to flight evolving twice - once in birds and once among the Gondwanan dromaeosaurs.
Dr Peter Makovicky, from the Field Museum in Chicago, whose research describing the new dinosaur appears in the journal Nature, said: "Buitreraptor is one of those special fossils that tells a bigger story about the Earth's history and the timing of evolutionary events.
"It not only provides definitive evidence for a more global distribution and a longer history for dromaeosaurs than was previously known, but also suggests that dromaeosaurs on northern and southern continents took different evolutionary routes after the landmasses they occupied drifted apart."
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