Named By: X. Xu, D.-Y. Wang, C. Sullivan, D. W. E. Hone, F.-L. Han, R.-H. Yan & F.-M. Du - 2010.
Classification: Choradata, Reptilia, Dinosauria, Saurischia, Alvarezsauridae, Parvicursorinae, Ceratonykini.
Species: X. zhangi (type).
Size: About 50 centimetres long.
Known locations: China, Henan Province, Xixia County - Majiacun Formation.
Time period: Santonian/Coniacian of the Cretaceous.
Fossil representation: Partial but articulated post cranial skeleton.
the time of its description the genus Xixianykus
represents the oldest
known parvicursorine alvarezsaur
discovered (others are dated to the
Campanian/Maastrichtian eras). The legs of Xixianykus
particular interest since they are about twenty centimetres long,
which in relation to a total body length estimated at fifty
centimetres long, means that Xixianykus had one
of the longest leg to
body length ratios of not just alvarezsaurs, but dinosaurs in
general. This meant that despite the small size, Xixianykus
have been exceptionally fast runners, perhaps even being able to
outpace potential predators such as dromaeosaurids.
A possible predatory threat and genus that Xixianykus should not be confused due to name similarity is the troodontid genus Xixiasaurus.
- A basal parvicursorine (Theropoda: Alvarezsauridae) from the Upper Cretaceous of China - X. Xu, D.-Y. Wang, C. Sullivan, D. W. E. Hone, F.-L. Han, R.-H. Yan & F.-M. Du - 2010.