Wednesday, June 7, 2017

[Paleontology • 2017] Liaoningvenator curriei • A New Troodontid Dinosaur from the Early Cretaceous Yixian Formation in Western Liaoning, China

Liaoningvenator curriei  
Shen, Zhao, Gao, Lü & Kundrát, 2017

reconstruction by Chuang ZHAO || DOI: 10.3975/cagsb.2017.03.06 


      A new troodontidLiaoningvenator curriei gen. et sp. nov., is described based on a complete skeleton from the Early Cretaceous Yixian Formation of Beipiao City, Liaoning Province. It bears the following characteristics of Troodontidae: numerous and more closely appressed maxillary and dentary teeth; the teeth markedly constricted between the roots and crowns; the nutrient foramina in groove on the external surface of dentary; distal caudal vertebrae having a sulcus on the dorsal midline rather than a neural spine. Unlike other troodontids, Liaoningvenator exhibits a sub-triangular ischial boot in lateral view and slender ischial obturator process; transition point in caudal vertebrae starts from the seventh caudal vertebra. A phylogenetic analysis recovers Liaoningvenator and Eosinopteryx as sister taxa that belong to the same clade. These two taxa share the following three characteristics: (1) anterior maxillary and dentary teeth lack serrations along the anterior carina; (2) shafts of cervical ribs are longer than vertebral centra with which they articulate; and (3) anterior margin of ilium is straight. The histological study indicates that Liaoningvenator was attaining skeletal maturity and at least four years old when it perished. Liaoningvenator represents the fifth troodontid taxon from the Lower Cretaceous equivalent strata of western Liaoning. It provides much new anatomical information on basal troodontid dinosaurs in this region. It also enhances the diversity of the troodontids in Early Cretaceous of China currently known.

Keywords: troodontid, new genus and species, Early Cretaceous, phylogenetic analysis, western Liaoning

Fig. 1 Line drawing (A) and photograph (B) of Liaoningvenator curriei gen. et sp. nov. (DNHM D3012)
Systematic paleontology
Theropoda Marsh, 1881
Maniraptora Gauthier, 1986
Troodontidae Gilmore, 1924

Liaoningvenator curriei gen. et sp. nov.  

Etymology: The genus name refers to Liaoning, and “venator” meaning hunter; the specific name honors Professor Philip J. Currie for his outstanding contribution to the research on small theropod dinosaurs.

Holotype: A nearly complete, naturally articulated skeleton with skull and lower jaws (DNHM D3012), all bones are three dimensionally preserved. The type specimen is housed in the collections of the Dalian Natural History Museum (DNHM), Dalian City, Liaoning Province, China.

 Type locality and horizon: Lujiatun, Shangyuan, Beipiao City, Liaoning Province, China; fluvial and volcaniclastic beds of the basal Yixian Formation, Hauterivian, Lower Cretaceous (Xu et al., 2002).

The reconstruction of Liaoningvenator curriei gen. et sp. nov. (DNHM D3012)
drawn by ZHAO Chuang

Cai-zhi Shen, Bo Zhao, Chun-ling Gao, Jun-chang Lü and Martin Kundrát. 2017. A New Troodontid Dinosaur (Liaoningvenator curriei gen. et sp. nov.) from the Early Cretaceous Yixian Formation in Western Liaoning Province. Acta Geoscientica Sinica. 38: 359-371.  DOI: 10.3975/cagsb.2017.03.06

Liaoningvenator, a new troodontid from China @wildprehistory