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Temporal range: Late Jurassic, 160 Ma
Holotype specimen
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Saurischia
Suborder: Theropoda
Superfamily: Alvarezsauroidea
Genus: Haplocheirus
Choiniere et al., 2010
Type species
Haplocheirus sollers
Choiniere et al., 2010
Size of Haplocheirus compared to a human.

Haplocheirus is a genus of alvarezsauroid theropod dinosaur. It is the oldest known alvarezsauroid, predating all other members by about 63 million years.[1] Haplocheirus was described in 2010 from a fossil specimen found from the 160-million-year-old Shishugou Formation in the Junggar Basin of northwestern China. The type species is H. sollers, meaning "simple-handed skillful one", referencing its hypothesized behavior of using its three-fingered hands for activities other alvarezsauroids couldn't, such as catching prey.[1][2]


Life restoration

Haplocheirus was the largest known definite alvarezsauroid, at around 2 meters long. It had an enlarged thumb claw like other alvarezsauroids, but also retained two other functional fingers, unlike more derived alvarezsauroids, where only the thumb was significantly large and clawed. It had long legs and was probably a fast runner.

See also[edit]


  1. ^ a b Choiniere, J. N.; Xu, X.; Clark, J. M.; Forster, C. A.; Guo, Y.; Han, F. (2010). "A basal alvarezsauroid theropod from the Early Late Jurassic of Xinjiang, China". Science. 327 (5965): 571–574. doi:10.1126/science.1182143. PMID 20110503.
  2. ^ Choiniere, J. (2010). Guest Post: Haplocheirus, the Skillful One Dave Hone's Archosaur Musings, April 23, 2011.

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