Saturday, April 9, 2016

[Paleontology • 2017] Datonglong tianzhenensis • A New Hadrosauroid Dinosaur from the Late Cretaceous of Tianzhen, Shanxi Province, China

Datonglong tianzhenensis  
 Xu, You, Wang, Wang, Yi & Jia, 2016

 A new non-hadrosaurid hadrosauroid dinosaur (Datonglong tianzhenensis gen. et sp. nov.) is reported. The new taxon is recovered from the Upper Cretaceous Huiquanpu Formation of Tianzhen County, Shanxi Province in northern China, and represented by an almost complete right dentary with dentition. Different from all other hadrosauroids, Datonglong possesses two functional teeth in each alveolus, and the pattern of ridge development on the lingual surface of its dentary crown shows a unique combination of character states (for example: distally offset primary ridge; well-developed secondary ridge; no additional ridge(s); slightly distally curved apical half of primary ridge). Comparative studies indicate advanced non-hadrosaurid hadrosauroids experienced a complex pattern in the evolution of their dentary, especially dentary dentition. Derived hadrosaurid features occurred frequently in these taxa, such as high height/width ratio of tooth crown in Bactrosaurus, one primary and one faint ridges in Gilmoreosaurus, median placed primary ridge in Zhanghenglong, rostrally inclined coronoid process in Nanningosaurus, and two functional teeth in each alveolus in Datonglong. This implies incredible diversities and attempts close to the origin of Hadrosauridae and difficulties to elucidate their phylogenetic relationships.

Key words: Tianzhen, Shanxi; Late Cretaceous; dinosaur, hadrosauroid

Fig. 2 Photos of right dentary of Datonglong tianzhenensis gen. et sp. nov. (SXMG V 00005)
A. lateral view; B: medial view. C: dorsal view; D. caudal view; E. close-up of partial dentition in B; E is not in scale

Systematic paleontology

Dinosauria Owen, 1842
Ornithischia Seeley, 1887
Ornithopoda Marsh, 1881

Iguanodontia Dollo, 1888 sensu Sereno, 2005
Ankylopollexia Sereno, 1986 sensu Sereno, 2005
Styracosterna Sereno, 1986 sensu Sereno, 2005

Hadrosauriformes Sereno, 1997 sensu Sereno, 1998
Hadrosauroidea Sereno, 1986 sensu Sereno, 2005

Datonglong gen. nov.
Datonglong tianzhenensis sp. nov.

Holotype: SXMG V 00005, almost complete right dentary with dentition.

Etymology: The generic name “Datong” is after “Datong City”, and Tianzhen is a county belonging to it; “long” means “dragon” in Chinese. The specific name “Tianzhen” is after “Tianzhen County”, where the current material is discovered.

Locality and horizon: Kangdailiang Quarry, Tianzhen County, Datong City, Shanxi Province, China. Huiquanpu Formation, Upper Cretaceous.

 Shi-Chao Xu, Hai-Lu You, Jia-Wei Wang, Suo-Zhu Wang, Jian Yi and Lei Jia. 2016. A New Hadrosauroid Dinosaur from the Late Cretaceous of Tianzhen, Shanxi Province, China. Vertebrata PalAsiatica. 54(1): 67−78. 
New hadrosauroid dinosaur found from the late Cretaceous of Shanxi, China via @physorg_com