'''Liaoningosaurus''' (
Xu, Wang, et You,
2001) is a very unusual ankylosaur from the Lower
Cretaceous. The
holotype (IVPP V12560; Institute of
Vertebrate Paleontology and
Paleoanthropology,
Beijing), an essentially complete juvenile
skeleton, was collected from the
Yixian Formation (
Barremian) of Liaoxi, Yixian County,
Liaoning Province,
People's Republic of China. The articulated skeleton measures approximately 34 cm in length, giving it the distinction of being the smallest-known ankylosaur. This
taxon is unique among all known ankylosaurs in the retention of the external mandibular
fenestra. Antorbital fenestrae may also be present. Another unique feature is the presence of ventral armor plating, sculpted
hexagonal and
rhombic osteoderms, unknown in other
ankylosaurians. Xu ''et al.'' (2001) place ''Liaoningosaurus'' within the
Nodosauridae, while Vickaryous ''et al.'' (
2004) have provisionally assigned it to the
Ankylosauria ''
incertae sedis''.
References
★ Xu, X., Wang, X.-L., and You, H.-L. 2001. A juvenile ankylosaur from China. Naturwissenshaften 88(7): 297-300.
★ Vickaryous, Maryanska, and Weishampel 2004. Chapter Seventeen: Ankylosauria. in The Dinosauria (2nd edition), Weishampel, D. B., Dodson, P., and Osmólska, H., editors. University of California Press.