Tuesday, April 4, 2017

[Paleontology • 2017] Shuangbaisaurus anlongbaoensis • A New Crested Theropod Dinosaur from the Early Jurassic of Yunnan Province, China


Shuangbaisaurus anlongbaoensis 
Wang, You, Pan & Wang, 2017 

  
Abstract
A new crested theropod, Shuangbaisaurus anlongbaoensis gen. et sp. nov., is reported. The new taxon is recovered from the Lower Jurassic Fengjiahe Formation of Shuangbai County, Chuxiong Yi Autonomous Prefecture, Yunnan Province, and is represented by a partial cranium. Shuangbaisaurus is unique in possessing parasagittal crests along the orbital dorsal rims. It is also distinguishable from the other two lager-bodied parasagittal crested Early Jurassic theropods (Dilophosaurus and Sinosaurus) by a unique combination of features, such as higher than long premaxillary body, elevated ventral edge of the premaxilla, and small upper temporal fenestra. Comparative morphological study indicates that “Dilophosaurus” sinensis could potentially be assigned to Sinosaurus, but probably not to the type species. The discovery of Shuangbaisaurus will help elucidate the evolution of basal theropods, especially the role of various bony cranial ornamentations had played in the differentiation of early theropods.

Key words:   Chuxiong; Early Jurassic; crest; dinosaur; theropod

Fig. 2 Cranium of Shuangbaisaurus anlongbaoensis (CPM C2140ZA245) in right lateral view. 

Dinosauria Owen, 1842 
Saurischia Seeley, 1887 
Theropoda Marsh, 1881

 Shuangbaisaurus gen. nov. 

EtymologyShuangbai” is the Chinese name of the county where the holotype was recovered, and this county was first established in West Han Dynasty (AD 109). “Sauros” is Greek for lizard.

Type species Shuangbaisaurus anlongbaoensis sp. nov. 

Diagnosis As for type and only known species (see below). 


Shuangbaisaurus anlongbaoensis gen. et sp. nov. 

Etymology Anlongbao” is the Chinese name of the town where the holotype was recovered, and it literally means dragon-placing fort. 

Holotype CPM C2140ZA245, a partial skull with lower jaw. Type locality and horizon Liuna Village, Anlongbao Town, Shuangbai County, Chuxiong Yi Autonomous Prefecture, Yunnan Province. The specimen was from the dark purple muddy siltstones in the lower part of the Lower Jurassic Fengjiahe Formation.

 Diagnosis Basal theropod distinguished by having parasagittal crests at least along orbital dorsal rims. Shuangbaisaurus also possesses a unique combination of features, including elevated ventral edge of the premaxilla (also present in Dilophosaurus and LFGT LDM-L10 of Sinosaurus), higher than long premaxillary body (also present in LFGT LDM-L10 of Sinosaurus, but longer than high in Dilophosaurus and KMV 8701 of Sinosaurus), and small upper temporal fenestra with its diameter shorter than the transverse width of the parietals in between and about half the length of the skull table posterior to the orbit


 WANG Guo-Fu, YOU Hai-Lu, PAN Shi-Gang and WANG Tao. 2017. A New Crested Theropod Dinosaur from the Early Jurassic of Yunnan Province, China.
 VERTEBRATA PALASIATICA. www.IVPP.ac.cn/cbw/gjzdwxb/pressonline/201703/t20170329_4765824.html

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