Linhenykus

materials. . .|left|238x238px Linhenykus was a small dinosaur, measuring long and weighing . Its femur length is . Although a reduced third metacarpal is present, the phalanges or finger bones of the third digit was entirely lost. The fourth metacarpal is not preserved in the Linhenykus holotype, but given that digit III is a reduced structure lacking phalanges, it is probable that this metacarpal is entirely absent in Linhenykus. Despite having the most reduced digits of any alvarezsauroid, Linhenykus was shown by cladistic analysis to have been a basal form as is indicated by the fact that its enlarged digit is not as large or robust as with more advanced forms. Some scientists have suggested Linhenykus, like other alvarezsaurids, was insectivorous, using its claws to dig into ant and termite nests, similar to modern anteaters. ==Discovery==

The fossil of Linhenykus was collected by Jonah N. Choiniere and Michael Pittman from the Late Cretaceous Wulansuhai Formation of Nei Mongol (Inner Mongolia), China. Biostratigraphic and lithographic correlations suggest that the formation dates to the Campanian and Maastrichtian stages, 75-71 Ma. Linhenykus is currently known from a partial skeleton, holotype IVPP V17608, including cervical, dorsal, sacral and caudal vertebrae, forelimb, hindlimbs, and pelvis, and a referred complete pes (anatomy). The genus was first described and named in the Proceedings of the National Academy of Sciences by Xu Xing, Corwin Sullivan, Pittman, Choiniere, David Hone, Paul Upchurch, Tan Qingwei, Xiao Dong, Lin Tan and Han Fenglu in 2011. The latter found statistically significant biogeographic reconstructions suggesting a dominant role for sympatric (or ‘within area’) events, combined with a mix of vicariance, dispersal and regional extinction. It has been suggested that Linhenykus may be a junior synonym of Parvicursor, but this interpretation was rejected by the original authors and has not been adopted in subsequent research on alvarezsauroids. ==Classification==

The cladogram below shows the phylogenetic position among alvarezsaurids following Makovicky, Apesteguía and Gianechini (2012). }} ==References==