Cranial anatomy of Citipati osmolskae (Theropoda, Oviraptorosauria), and a reinterpretation of the holotype of Oviraptor philoceratops

Related Titles

Series: American Museum novitates, no. 3364

By

Clark, James Matthew, 1956-

Norell, Mark A.
Rowe, Timothy, 1953-
Mongolian-American Museum Paleontological Project.
Mongolyn Shinzhlėkh Ukhaany Akademi.
Central Asiatic Expeditions 1921-1930

Type

Book

Material

Published material

Publication info

New York, NY American Museum of Natural History c2002

Notes

Caption title.

"March 26, 2002."

Specimen of Citipati osmolskae collected from the Djadokhta Formation at Ukhaa Tolgod, Mongolia, during the Mongolian Academy of Sciences-American Museum of Natural History Expeditions to the Gobi Desert; holotype of Oviraptor philoceratops collected in 1924 during the 1921-1930 Central Asiatic Expeditions.

We describe the skull of the holotype of Citipati osmolskae, one of the best preserved oviraptorid skulls known. The skull preserves stapes and epipterygoids, and the mandible preserves a slender coronoid bone, none of which has been reported before in oviraptorids. The braincase is similar to that of other basal coelurosaurs but possesses extensive recesses presumably occupied by pneumatic diverticulae; the circumnarial region is highly pneumatized, and a large recess continues posteriorly from the narial region to invade the frontals and parietals dorsal to the braincase. Circum-otic pneumatic recesses include two dorsal recesses above the otic recess, a posterior recess on the anterior surface of the paroccipital process, and extensive cavities in the basisphenoid beneath the braincase. The more dorsal of the two dorsal tympanic recesses is very deep, and CT scans suggest that it connected medially across the midline dorsal to the otic region and anteriorly with the frontoparietal space. The otic recess is unusually shallow. Comparison of the new skull with the poorly preserved skull of the holotype of Oviraptor philoceratops demonstrates that the braincase and palate of the latter are similar to those of other oviraptorids. Its rostrum and dentary are more elongate than in other oviraptorids, however, a more plesiomorphic condition suggesting it may be the most basal oviraptorid. A well-preserved skeleton previously referred to O. philoceratops, IGM 100/42, does not belong to this genus or species, and its narial region is very similar to that of Citipati osmolskae.

Subjects

Citipati osmolskae , Cretaceous , Dinosaurs , Mongolia , Oviraptor philoceratops , Paleontology , Reptiles, Fossil , Skull

Call Number

QL1 .A436 no.3364 2002

Language

English

Identifiers

DOI: https://doi.org/10.1206/0003-0082(2002)364<0001:CAOCOT>2.0.CO;2
OCLC: 49536836