Neuquenraptor

Neuquenraptor
Temporal range: Late Cretaceous, 90Ma
↓
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Suborder: Theropoda
Family: †Dromaeosauridae
Subfamily: †Unenlagiinae
Genus: †Neuquenraptor
Novas & Pol, 2005
Species: †N. argentinus
Novas & Pol, 2005

Neuquenraptor is a dromaeosaurid theropod dinosaur of the Late Cretaceous of Argentina, one of the first dromaeosaurids found in the Southern Hemisphere.

In January 1996 the remains of Neuquenraptor were found near Plaza Huincul in the Sierra del Portezuelo and reported that very year.[1] In 1997 it was revealed the intended name was "Araucanoraptor argentinus". In 1999 it was provisionally described as a member of the Troodontidae.[2]

However, it was named as the type species Neuquenraptor argentinus in 2005 by Fernando Novas of the Bernardino Rivadavia Natural Sciences Museum and Diego Pol of Ohio State University and described as a dromaeosaurid. The generic name combines Neuquén, a province of Patagonia, Argentina, with Latin raptor meaning "thief". The specific name refers to Argentina.[3]

The known remains, holotype MCF-PVPH 77, were uncovered in layers of the Portezuelo Formation dating to the Coniacian. It consists of only a left foot, some cervical vertebrae fragments, ribs, tail chevrons and a radius.[3]

Neuquenraptor might be a junior subjective synonym of Unenlagia;[4] that is, the two might represent the same genus or even species, in which case the name Unenlagia would have to be used instead of Neuquenraptor because the former name was published earlier, in 1997, and thus has priority.[5]

Neuquenraptor is estimated to have measured 1.8 metres (5.9 ft) long.[6]

Neuquenraptor was assigned by Novas and Pol to the Dromaeosauridae in a polytomy with several dromaeosaurid taxa.[3] By later cladistic analyses it was recovered in the Unenlagiinae.

Neuquenraptor enjoys a special importance because of its provenance from South America. Until the discovery of Neuquenraptor, all dromaeosaurids had been found in North America, Europe or Northern China / Mongolia, and scientists believed that dromaeosaurids only inhabited Laurasia, i.e. the Northern Hemisphere. South America however, during the Mesozoic became part of Gondwana. The find of Neuquenraptor provides some possible indication of the degree of isolation between the Northern and Southern hemispheres.

The supercontinent Pangaea started to break up in the Early Jurassic, leading to the separation around 160 Ma of Laurasia in the north and Gondwana in the south. Gondwana itself was soon fragmented into West Gondwana (i.e., Africa + South America) and East Gondwana (i.e., (Antarctica+ Australia) + (India+Madagascar)). West Gondwana broke apart during the Cretaceous, as Africa and South America separated between 132 and 90 Ma. Between approximately 80 and 60 Ma, i.e. in the Late Cretaceous and early Paleocene, North America and South America were perhaps connected, at least episodically, by a land bridge, due to the eastward motion of the Caribbean plate between the two continental masses.

References

  1. ↑
    • Novas, F. E.; Cladera, G.; Puerta, P. (1996). "New theropods from the Late Cretaceous of Patagonia". Journal of Vertebrate Paleontology 16: 56A.
  2. ↑ Novas, Fernando E.; Apesteguia, Sebastian; Pol, Diego; Cambiaso, Andrea V. (1999). "Un probable troodontido (Theropoda-Coelurosauria) del Cretacico Tardio de Patagonia". Ameghiniana 36 (4): 17.
  3. ↑ 3.0 3.1 3.2 Novas, Fernando E.; Pol, Diego (2005). "New Evidence on Deinonychosaurian Dinosaurs from the Late Cretaceous of Patagonia". Nature 433 (7028): 858–861. Bibcode:2005Natur.433..858N. doi:10.1038/nature03285. PMID 15729340.
  4. ↑ Makovicky, Peter J.; Apesteguía, Sebastián; Agnolín, Federico L. (2005). "The Earliest Dromaeosaurid Theropod from South America" (PDF). Nature 437 (7061): 1007–1011. Bibcode:2005Natur.437.1007M. doi:10.1038/nature03996. PMID 16222297.
  5. ↑ Novas, Fernando E.; Puertat, Pablo F. (1997). "New Evidence Concerning Avian Origins from the Late Cretaceous of Patagonia". Nature 387 (6631): 390–392. Bibcode:1997Natur.387..390N. doi:10.1038/387390a0.
  6. ↑ Holtz, Thomas R. Jr. (2008) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages. New York: Random House, 2007. ISBN 978-0-375-82419-7. Supplementary Information.

External links