Introducing Corythoraptor jacobsi.

The cranial casque of Corythoraptor jacobsi and recent cassowaries (From Lü et al., 2017)

Oviraptorosaurs are a well-defined group of coelurosaurian dinosaurs, characterized by short, deep skulls with toothless jaws, pneumatized caudal vertebrae, anteriorly concave pubic shafts, and posteriorly curved ischia.  The most basal forms were small, similar to a chicken or a turkey. They have only been found in Asia and North America and include animals like Protarcheoepteryx, Caudipteryx, Microvenator, Avimimus, Anzu, and Citipati. The most famous dinosaur of this group, Oviraptor, was discovered in 1923 by Roy Chapman Andrews in Mongolia, associated with a nest of what was thought to be Protoceratops eggs. The misconception persisted until 1990s when it was revealed that the eggs actually belonged to Oviraptor, not Protoceratops. Since then, more skeletons of Oviraptor and other oviraptorids like Citipati and Nemegtomaia have been found brooding over their eggs.

The Ganzhou area in the Jiangxi Province, in southern China, is one of the most productive oviraptorosaurian regions of the world. Six oviraptorosaurian dinosaurs have been named from Ganzhou: Banji long, Jiangxisaurus ganzhouensis, Nankangia jiangxiensis, Ganzhousaurus nankangensis, Huanansaurus ganzhouensis, and Tongtianlong limosus.  

The holotype of Corythoraptor jacobsi gen. et sp. nov. (From Lü et al., 2017)

The new oviraptorid dinosaur unearthed from the Upper Cretaceous deposits of Ganzhou, was named Corythoraptor jacobsi. The generic name Corythoraptor refers to a raptor bearing a “cassowary-like crest” on its head. The holotype (JPM-2015-001), an almost complete skeleton with the skull and lower jaw, probably corresponds to a young adult that was approaching a stationary stage of development. The anterodorsal part of the crest is missing, but apparently the highest point of the crest would project far above the orbit. The internal structure of the crest is similar to the casque of Casuarius unappendiculatus. The extensive cranial casque was probably composed of the skull roofing bones: nasals, frontals and parietals. The inner structure consists of randomly branching, sparse, trabeculae of variable thickness ranging from 0.3 to 1.2 mm, which implies that the inner core was light, fragile, and not suitable for percussive behavior including intraspecific combat.

Corythoraptor jacobsi forms one clade with Huanansaurus ganzhouensis, but both mainly differs in the skull morphology and the structure of the cervical vertebrae. 

 

References:

Lü, J., Li, G., Kundrát, M., Lee, Y., Sun, Z., Kobayashi, Y., Shen, C., Teng, F., Liu, H. 2017. High diversity of the Ganzhou oviraptorid fauna increased by a new “cassowary-like” crested species. Scientific Reports. doi: 10.1038/s41598-017-05016-6

 

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