[N] 2006 Preliminary report of a new specimen of Chrirostenotes
Schachner, E., Lyson, T. and Hanks, H. (2006) a Preliminary report of a new specimen of Chrirostenotes (Oviraptorosauria-Theropoda) from the Hell Creek Formation of North Dakota. JVP 26(3) Abstracts pp.120
Chirostenotes is a rare and poorly known, medium sized theropod dinosaur from the Late Cretaceous of North America. The genus is known mostly from cranial fragments, the vertebral column, and distal hindlimb and manual elements. Recent collections in channel sandstone deposits of the Hell Creek Formation (North Dakota) have resulted in the discovery a new specimen of Chirostenotes composed of multiple corresponding postcranial elements. Recovered elements include three cervical vertebrae, a complete scapulocoracoid, a radius, an ulna, and a single dorsal rib.
The genus Chirostenotes encompasses two morphs that have been divided into distinct species, C. pergracilis and C. elegans, however there are no diagnostic features on the new specimen that allow for any conclusive species assignment. The vertebrae of the new specimen share the following features with previously described specimens: the centrum is long and narrow, there are pleurocoels in the centrum, the neural arch is low and broad, and the transverse processes are robust and subtriangular in transverse section. An unusual feature of the new specimen is the fusion of the cervical ribs with both the transverse processes and the ventral portion of the centrum. The scapulocoracoid is a single fused element indicative of an adult individual. The radius and ulna are approximately equal in length, and the ulna is bowed as in other oviraptors. The scapula, radius, and ulna are all elements previously undescribed for the genus Chirostenotes. Due to the general paucity of oviraptorosaurian remains this specimen should help to resolve some of the phylogenetic ambiguities within this group.