Ceratonykus

Ceratonykus (meaning "horned claw") is a monospecific genus of alvarezsaurid dinosaur from Mongolia that lived during the Late Cretaceous (Maastrichtian) in what is now the Barun Goyot Formation. The type and only species, Ceratonykus oculatus, is known from a fragmentary skeleton, including an incomplete skull, of an adult individual. It was named and described in 2009 by Vladimir Alifanov and Rinchen Barsbold. Its describers questioned the traditional placement of alvarezsaurs in Theropoda, instead suggesting they were ornithischians, but this has not been accepted since. Ceratonykus has an estimated length of and weight of . It has been considered as a possible junior synonym of Parvicursor.

==Discovery and naming== thumb|left|200px|Fossil localities in Mongolia. Ceratonykus fossils have been collected at Hermiin Tsav (area A) In 2003, a partial skeleton of an alvarezsaurid was discovered in the Barun Goyot Formation of the Khermiin Tsav locality, Mongolia by the Paleontological Center of the Mongolian Academy of Sciences (MPC) preparator Otkhoon Zhargal. The skeleton was enclosed in two pieces of rock during the time of the discovery. The specimen was subsequently named and described in 2009 by Vladimir Alifanov and Rinchen Barsbold. The holotype specimen, MPC no. 100/124, consists of an incomplete skull and lower jaw, cervical vertebrae, caudal vertebrae, sternum, left and right coracoids, a right humeral fragment, distal elements of forelimbs, fragmentary ilium, and hindlimbs. The specimen is of an adult individual based on the fusion of the astragali and tibiae, with partially obliterated sutures.