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Temporal range: Late Cretaceous, 83 Ma
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Dinosauria
Order: Saurischia
Suborder: Theropoda
Family: Alvarezsauridae
Genus: Xixianykus
Xu et al, 2010
Species: X. zhangi
Binomial name
Xixianykus zhangi
Xu et al., 2010

Xixianykus is a genus of alvarezsauroid theropod dinosaur from the late Cretaceous period of China.[1]


The type species is Xixianykus zhangi described in 2010 by Xu Xing. The genus name refers to Xixia County and to the Greek word for claw ("nyx"). The latter is a common element used in names for Alvarezsaurids. The species name is in honor of Zhang Xinglao.


The fossil, holotype XMDFEC V0011, was found in the Majiacun Formation in Henan Province, China. The fossil consists of a partial skeleton, without the skull. Parts of the hind legs, pelvis and spine has also been recovered.


It is among the oldest of the derived alvarezsauroids, the parvicursorines, dated to the Santonian-Coniacian as opposed to other parvicursorines, which are either Campanian or Maastrichtian.[2]


Xixianykus was a small animal, about 50 cm long and 20 cm high. It is one of the smallest known dinosaurs (not counting avians). It appears to have many adaptations towards a cursorial (running) lifestyle. It was about 50 centimetres (20 in) long but had 20 centimetres (7.9 in) long legs and a short femur combined with a long tibia and metatarsus, which are good indicators of it being a fast runner.[2] It was probably covered in feathers.


  1. ^ Xu, X., Wang, D.Y., Sullivan, C., Hone, D.W.E., Han, F.L., Yan, R.H. and Du, F.M. (2010). "A basal parvicursorine (Theropoda: Alvarezsauridae) from the Upper Cretaceous of China.". Zootaxa, 2413: 1-19.
  2. ^ a b Hone, D. (2010). Xixianykus zhangi - A New Alvarezsaur Dave Hone's Archosaur Musings, April 23, 2011.

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