Artistic representation of live Noasaurus
- Argentina ( Lecho Formation)
- Noasaurus leali
Noasaurus is a genus theropod dinosaur from the group of Noasauridae. So far, a single fragmentary skeleton is only known that originates from the Upper Cretaceous ( Maastrichtian early ) of Argentina. The only way is Noasaurus leali.
The name Noasaurus means as much as " lizard from northwestern Argentina " (NOA is an abbreviation for span noroeste Argentinia - " Northwestern Argentina "; sauros gr - "lizard ").
Noasaurus was a relatively small, bipedal running predators with an estimated length of about 1.5 meters. The specimen found includes a strongly curved claw with a. While it was initially believed that this claw was sitting on the second toe of the foot - analogous to the " sickle claws" of Deinonychosauria - are recent studies to the conclusion that there was indeed a hand claw. The snout was viewed from the side dull, whereupon a high and short premaxillary bone ( premaxilla ) suggests - a typical representative of the Abelisauridae feature. In the maxilla, found only 11 tooth positions are available, some with preserved teeth were slightly curved and serrated on both sides. Found parts of the cervical vertebrae indicate numerous cavities ( pneumatization ) and exhibit a particular morphology of the on- top extensions which otherwise only derived ( advanced ) representatives of Abelisauridae as Carnotaurus is found in this form: To the spinous processes were low, during which located behind the spinous processes Epipophysen were greatly extended.
Research history, systematics and Fund
Noasaurus was already described in 1980 by José Fernando Bonaparte and Jaime Powell. These authors classified Noasaurus in a separate family, the Noasauridae to reflect the significant anatomical differences to other then-known theropod account. Only in 2001 was described with Masiakasaurus a better -known members of this family. The relationships within the Noasauridae are unclear.
The only Fund ( holotype, specimen number PVL 4061 ) comes from El Brete the southern Argentine province of Salta. It includes bones from different parts of the skeleton: for instance skull bones ( upper jaw with teeth and a square leg ), handed vortex (fragments of each of a neck and a dorsal and two cervical ribs ), a metatarsal, and phalanges and hand claws.
The finding comes from the Lecho Formation, which is known for its rich vertebrate fauna. Discoveries of dinosaurs and birds from this formation include the Titanosaurier Saltasaurus and the early birds Enantiornis, Soroavisaurus, Yungavolucris and Lectavis with a.
- Fernando E. Novas: The age of dinosaurs in South America. Indiana University Press, Bloomington 2009, ISBN 978-0-253-35289-7.
- Matthew Carrano, Scott Sampson: The Phylogeny of Ceratosauria ( Dinosauria: Theropoda ). In: Journal of Systematic Palaeontology. 6, 2008, pp. 183-236.
- Federico Agnolin, Pablo Chiarelli: The position of the claws in Noasauridae ( Dinosauria: Abelisauroidea ) and its implications for abelisauroid manus evolution. In: Paleontological Journal. 84, No. 2, May 1 2010, pp. 293-300, doi: 10.1007/s12542-009-0044-2 ().