Shanag

Shanag is a genus of dromaeosaurid theropod dinosaur from the Early Cretaceous Period of Mongolia. The type species of Shanag is S. ashile. It was named and described by Alan Turner, Sunny Hai-Ching Hwang and Mark Norell in 2007. The generic name refers to the black-hatted dancers in the Buddhist Cham dance. The specific name refers to the Ashile Formation, the old name for the layers where Shanag was found, used by Henry Fairfield Osborn. The holotype of Shanag, IGM 100/1119, was discovered in the Öösh Formation, the stratification of which is uncertain but probably dating to the Berriasian-Barremian. Shanag bears a strong resemblance to basal Chinese dromaeosaurids such as Microraptor and Sinornithosaurus, suggesting a close similarity between the fauna of the Öösh deposits, dated tentatively to 130 million years ago, and the Jehol Biota of China (such as the animals found in the roughly contemporary Yixian Formation), during the Early Cretaceous. Shanag was a small predator. In 2010 Gregory S. Paul estimated its length at 1.5 meters, the weight at five kilograms. Shanag shows a mixture of dromaeosaurid, troodontid and basal avialan traits. Turner et al. assigned Shanag to the Dromaeosauridae. Their cladistic analysis indicated that it was a basal dromaeosaurid but higher in the tree than the Unenlagiinae. Later analyses recovered it in the Microraptorinae. The holotype specimen, about six centimeters long, is composed of an associated uncompressed upper and lower jaw fragment, containing a nearly complete right maxilla with teeth, a partial right dentary with teeth and an attached partial splenial. The fossilized teeth in the specimen were pointed with serrations along the lengths of the posterior teeth, but no anterior teeth were available. Shanag is autopomorphic as it lacks promaxillary fenestra and has interalveolar pneumatic cavities, which separates it from its nearest relative of S. millenii. Its teeth have unusually long root lengths, making up about 70% of the overall tooth length.