Buitreraptor

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Buitreraptor

Buitreraptor skeleton at the Field Museum of Natural History.

Conservation status

Extinct (fossil)

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Superorder:	Dinosauria
Order:	Saurischia
Suborder:	Theropoda
Infraorder:	Coelurosauria
Family:	Dromaeosauridae
Subfamily:	Unenlagiinae
Genus:	Buitreraptor

Binomial name

Buitreraptor gonzalezorum
Makovicky, Apesteguía & Agnolin, 2005

Buitreraptor was a rooster-size predatory dinosaur belonging to the dromaeosaurid family. It was found in Argentina and was described in 2005.

Buitreraptor gonzalezorum is the only known species of the genus Buitreraptor. The generic name means "vulture raider", from the Spanish word buitre meaning vulture. Furthermore, the area in which the remains were found is called La Buitrera.

Buitreraptor lived about 90 million years ago, when South America was an isolated continent like Australia today. Buitreraptor has some different physical features than typical northern dromaeosaurs, like Velociraptor. Buitreraptor has a slender snout with teeth that lack meat-tearing serrations. From this scientists conclude that this dinosaur was not a big-game hunter like most other dromaeosaurs, but a hunter of small animals such as lizards and mammals. Its long bird-like arms confirm such a life of grasping fast-moving small prey. It has long legs and must have been an agile runner. It most likely had feathers. This dromaeosaur occupied a niche like that of modern secretarybirds or even the dinosaur Troodon from North America.

Buitreraptor (front) and Deinonychus (back) skeletons at the Field Museum of Natural History.

Other than Buitreraptor, the only other known dromaeosaurs from the southern continents are Neuquenraptor and Unenlagia from South America (discovered earlier in 2005), Rahonavis (once thought to be a true avian bird) from Madagascar, and unidentified dromaeosaur-like teeth from Australia. The bones in both Buitreraptor and Rahonavis show either that powered flight evolved independently in two different groups of dinosaurs: birds and southern dromaeosaurs, or that flight evolved once in the ancestor of dromaeosaurs, and subsequently the two dromaeosaur lines (northern and southern) became secondarily flightless.

This discovery in the Southern Hemisphere confirms that dinosaurs were more widely dispersed around the world than previously thought. Scientists now think that dromaeosaurs date back to Jurassic times, when all the continents were much closer together. It is possible that they originated on the ancient continent Laurasia in the north and migrated to southern Gondwana later.

The fossilised bones were found in 2005 in sandstone in Patagonia, Argentina - by an excavation lead by Peter Makovicky, curator of dinosaurs at the Field Museum in Chicago). Buitreraptor was discovered in the same fossil site that had earlier yielded Giganotosaurus, one of the largest known carnivorous dinosaurs.