Tuesday, November 15, 2016

[Paleontology • 2016] Tongtianlong limosus • A Late Cretaceous Diversification of Asian Oviraptorid Dinosaurs: Evidence from A New Species preserved in An Unusual Posture

Tongtianlong limosus 
Lü, Chen, Brusatte, Zhu & Shen, 2016

 An artistic reconstruction, showing the last-ditch struggle of Tongtianlong limosus as it was mired in mud, one possible, but highly speculative, interpretation for how the specimen was killed and buried.
(Drawn by Zhao Chuang)  DOI: 10.1038/srep35780  

Oviraptorosaurs are a bizarre group of bird-like theropod dinosaurs, the derived forms of which have shortened, toothless skulls, and which diverged from close relatives by developing peculiar feeding adaptations. Although once among the most mysterious of dinosaurs, oviraptorosaurs are becoming better understood with the discovery of many new fossils in Asia and North America. The Ganzhou area of southern China is emerging as a hotspot of oviraptorosaur discoveries, as over the past half decade five new monotypic genera have been found in the latest Cretaceous (Maastrichtian) deposits of this region. We here report a sixth diagnostic oviraptorosaur from Ganzhou, Tongtianlong limosus gen. et sp. nov., represented by a remarkably well-preserved specimen in an unusual splayed-limb and raised-head posture. Tongtianlong is a derived oviraptorid oviraptorosaur, differentiated from other species by its unique dome-like skull roof, highly convex premaxilla, and other features of the skull. The large number of oviraptorosaurs from Ganzhou, which often differ in cranial morphologies related to feeding, document an evolutionary radiation of these dinosaurs during the very latest Cretaceous of Asia, which helped establish one of the last diverse dinosaur faunas before the end-Cretaceous extinction.

Figure 2: The whole skeleton of the holotype Tongtianlong limosus gen. et sp. nov. in dorsal view (a) and lateral view (b). Scale bar = 10 cm. 

Systematic Paleontology

Dinosauria Owen, 184231.

Theropoda Marsh, 188132.
Maniraptora Gauthier, 198633.

Oviraptorosauria Barsbold, 197634.
Oviraptoridae Barsbold, 197634.

Tongtianlong limosus gen. et sp. nov. (Figs 2, 3 and 4)

Holotype: A nearly complete, three-dimensionally preserved skeleton with skull and lower jaws (DYM-2013-8). The specimen is accessioned at the Dongyang Museum, Dongyang City, Zhejiang Province.

Type locality and horizon: The building site of the No. 3 high school of Ganxian (GPS coordinates are provided on request from the first author); Nanxiong Formation (Maastrichtian, Upper Cretaceous).

Etymology: Tongtian, Chinese Pinyin, refers to Tongtianyan of Ganzhou, the first grotto south of the Yangtze River. Tongtian also means the road to heaven, a fitting epitaph for a deceased dinosaur preserved with outstretched arms. Long, Chinese Pinyin for dragon. Limosus, Latin for muddy, refers to the holotype specimen being found in an unusual posture in a mudstone (Fig. 5).

Junchang Lü, Rongjun Chen, Stephen L. Brusatte, Yangxiao Zhu and Caizhi Shen. 2016. A Late Cretaceous Diversification of Asian Oviraptorid Dinosaurs: Evidence from A New Species preserved in An Unusual Posture. Scientific Reports. 6, Article number: 35780. DOI: 10.1038/srep35780


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