Corythoraptor
Corythoraptor (lit. 'helmeted thief') is a genus of oviraptorid dinosaur from the late Maastrichtian Nanxiong Formation of South China. It contains one species, C. jacobsi, known from a single well-preserved skeleton, and named after paleontologist Louis L. Jacobs. It bears a tall crest similar to that of the modern cassowary, and possibly had a similar functionality of display and resonance to detect lower-frequency sounds.
Like other oviraptorids, the bones of Corythoraptor were heavily pneumatized with many air pockets. Microanalysis of the bones indicates seasonal growth spurts, and the type specimen probably died at the age of 6 or 7, meaning growth continued into at least the 8th year of development. The type specimen reached 1.6 m (5 ft 3 in) in length. Oviraptorids may have predominantly inhabited arid environments and ate xerophytic (drought-resistant) plants, nuts, and seeds. However, Corythoraptor coexisted with six other oviraptorid genera, and they may have all eaten different foods (niche partitioning).
Corythoraptor was described by Chinese paleontologist Lü Junchang and colleagues in 2017. The holotype, JPM-2015-001, is a nearly complete skeleton of an individual at least seven or eight years old, lacking distal caudal vertebrae but including the skull and lower jaw (JPM-2015-001). It is one of better preserved oviraptorosaurian specimens known so far. It was discovered in the Late Cretaceous Nanxiong Formation near the Ganzhou Railway Station in Ganzhou, Jiangxi, in South China. The specimen is now kept at the Jinzhou Paleontological Museum in Jinzhou, Liaoning Province. It was not in a typical death pose, and the neck was in a circular curl much like the type specimen for the contemporary oviraptorid Heyuannia. What caused this is unclear.[1]
The name Corythoraptor is in reference to the distinct crest on its head. The species name jacobsi honors American vertebrate paleontologist Louis L. Jacobs who mentored three of the authors while they were getting their PhD's at Southern Methodist University, Dallas, Texas.[1]
Corythoraptor bore a tall crest on its head similar to that of the modern cassowary, with a 2 mm (0.079 in) thick perhaps keratinous bony shell casing. The crest is pneumatized and features several chambers separated by thin bony walls, though the crest of Corythoraptor is more pneumatized than that of the cassowary. This may have made the crest quite pliable, incapable of withstanding concussive force such as during head butting.[1]
Corythoraptor had a relatively large eyesocket. The nasal bones seem to be highly pneumatized. The lower part of the premaxillae (at the tip of the snout) features several irregularly distributed pits, which probably represent foramina which allowed blood vessels to flow, indicating a keratinous sheath (rhamphotheca) over a beak similar to ornithomimids. The ventral side (underside) of the premaxillae is highly broken up, which could indicate the bone was lightweight, perhaps being pneumatized. Corythoraptor was toothless.[1]
