Unenlagia

Live reconstruction of Unenlagia

• Argentina, Neuquén Province ( Portezuelo Formation)

Unenlagia is a genus theropod dinosaur from the group of Dromaeosauridae. Findings of this animal come from the Upper Cretaceous ( Turonian to Coniacian ) of the Argentine province of Neuquén.

So far, two species of this genus have been described: the type species Unenlagia comahuensis was scientifically described in 1997 and is based on a fragmentary skeleton without skull. A few bones were described in 2004 as a second type, Unenlagia paynemili.

Probably the feathered dinosaur Unenlagia shows many similarities with the birds, which is why it was originally proposed as a possible sister taxon of this group. Norell and Makovicky (1999), however, showed many similarities with this genus Dromaeosauriden. Today Unenlagia is usually classified within an original, limited to the southern continents Dromaeosauriden group that Unenlagiine.

Makovicky and colleagues ( 2005) suggest that the genus Neuquenraptor with Unenlagia was identical - this assumption is supported by some other authors.

Features

Unenlagia was a medium-sized Dromaeosauride - the holotype specimen is estimated to have a length of about 2 meters, the weight calculated a study to 105.7 kg. The length of the femur (thigh bone ) of the holotype specimen, a key for length comparisons size was about 38 cm.

Unenlagia similar in shape to the scapula, pelvis and rear legs of the Archaeopteryx. As with birds show the arm bone, the necessary modifications for folding the wing as well as for a strong wing beat, although Unenlagia was probably too big to fly. Unlike birds, however, were different primitive features of the pubic bone ( pubis ) and the ischium humps ( ischium ) and the proportions of the hind leg bones.

Described with Unenlagia paynemili Jorge Calvo and colleagues ( 2004), a second type, which shares with the type species Unenlagia comahuensis as a common feature ( synapomorphy ) that oriented to the rear lower end of the pubic bone. Other possible synapomorphy of the curved dorsal edge of the postacetabularen ilium ( ilium ) is specified. In contrast to Unenlagia comahuensis but Unenlagia paynemili possessed more delicate bone, a smaller angle between the lower edge of the Deltopectoralkamms and the humeral shaft at the upper arm bone (humerus ), a small process on the front side of the lower end of the pubis and a wider and gerundeteres distal end of the postacetabularen ilium.

Fund and naming

The first Fund, the holotype specimen of Unenlagia comahuensis ( copy number MCF PVPH 78), comes from the Portezuelo Formation ( late Turonian to early Coniacian ), a layer member of the Rio Neuquen - subgroup. It consists of the eighth, tenth and thirteenth back vertebrae, three dorsal fins, the sacrum ( sacrum ), two chevron bone, shoulder blade (scapula ), humerus (27 cm), ilium, pubis, ischium, femur and tibia ( 43.1 cm).

Further material was discovered in 2002 by a research team in Futalognko, an important reference 90 km northwest of the city of Neuquén for vertebrate fossils. The discovered remains isolated close the left upper arm bone and the left pubic bone with one, both bones probably belonged to the same individual. These bones form the holotype of Unenlagia paynemili and be under the copy number MUCPv -349. More of this type attributed to material from the same locality is a 2003 discovered vertebrae ( MUCPv -416 ) and the rear end of the right ilium ( MUCPv -409 ). For the time being also an isolated phalanx ( phalanx, MUCPv -415 ) and a claw ( ungual, MUCPv -343 ) from Futalognko Unenlagia paynemili is attributed.

Unenlagia comahuensis was described in 1997 by Novas and Puerta. The name Unenlagia comes from the Mapuche language and means " half- bird" ( unde - "half" and was - " bird "). The Artepitheth the second type described paynemili 2004 honors Maximino Paynemil, the chief of an Indian community living in the region of Futalognko - discovery site.

Swell

• JO Calvo, JD Porphyrius, AW Kellner: On a new maniraptoran dinosaur ( Theropoda ) from the Upper Cretaceous of Neuquén, Patagonia, Argentina. In: Arq. Mus. Nacional. Rio de Janeiro. 62, 2004, pp. 549-566.