Buitreraptor

Buitreraptor gonzalezorum in the Field Museum of Natural History

  • Argentina, Río Negro Province ( Candeleros Formation)

Buitreraptor is a genus theropod dinosaur from the group of Dromaeosauridae. Remains of this animal come from the early Late Cretaceous ( Cenomanian ) of the Argentine province of Río Negro.

So far, a nearly complete skeleton and a partial skeleton are known. Buitreraptor was described in 2005 with the single species so far Buitreraptor gonzalezorum scientifically. It is attributed to the Unenlagiinae, a group of basal Dromaeosauriden the southern continents.

Features

Buitreraptor was a small Dromaeosauridae with an estimated length of 1.25 m and a weight of 4.7 kg. The length of the femur (thigh bone ), a key length for size comparisons, was approximately 14.5 cm.

The skull was flat and proportionally much longer than most other theropods; so he surpassed the femur in length by 25%. The flat and thin nose pointed to a long, thin snout, similar to that of Velociraptor. Like other Dromaeosauriden decreed Buitreraptor a good spatial vision, after which seen from above triangular shape of the skull suggests. Very atypical for Dromaeosauriden are very small, ungesägten teeth that stuck with increased distance from each other in the jaw.

As with other Dromaeosauriden was the tail by mechanical fasteners - extended prezygapophyses and chevron bones - amplified. In contrast to the Dromaeosauriden Laurasias, in which a single of these vortices excesses could overlap to ten preceding vertebrae, which prezygapophyses were pointed at Buitreraptor and overlapped only half of the first preceding vertebra. A unique feature of Buitreraptor was the broad, robust and pneumatized ( laced with cavities ) wishbone ( furcula ). The pubis ( pubic ) oriented perpendicular - a common feature of all Unenlagiinen. The metatarsals showed a arctometatarsale position: So touched the second and fourth metatarsals and the third pushed back so this was visible from the front, only the lower part of the midfoot.

Fund and naming

The findings are from " La Buitrera ", a rich fossil reference of Candeleros formation, a layer member of the Neuquen Group. The fluvial sandstones of this reference are known for their well-preserved, three-dimensional skeletons of small tetrapods, as Sphenodontiden, crocodiles from the group of Araripesuchiden, primitive, legged snakes and mammals such as Dryolestoiden while dinosaurs are rare. However, other, nearby outcrops of Candeleros lineup contained remains of large dinosaurs like Rebbachisauriden, basal titanosaurs and Carcharodontosauriden.

The holotype material of Buitreraptor ( copy number MPCA 245 ) is a nearly complete skeleton of an adult animal, the only missing parts of the lower legs and arms, and the rear half of the tail. In another Fund ( copy number MPCA 238) is a partial skeleton that consists of pelvic bones, the sacrum and the right hind leg. Both finds are in the collection of the Museo Carlos Ameghino in Cipolletti.

The name Buitreraptor has the locality " La Buitrera " (Spanish el buitre - " Vultures " ) out with raptor " robber " means. The Artepitheth gonzalezorum honors the brothers Fabián González and Jorge, who helped over the years in the field work in " La Buitrera ".

Swell

  • Peter J. Makovicky, Apesteguia Sebastián, Federico L. Agnolin: The earliest dromaeosaurid theropod from South America. In: Nature. 437, 2005, pp. 1007-1011, doi: 10.1038/nature03996.
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