Shibata Masateru, Jintasakul Pratueng, Azuma Yoichi, You Hai-Lu
Institute of Dinosaur Research, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-Cho, Fukui, 910-1195, Japan.
Fukui Prefectural Dinosaur Museum, 51-11 Muroko, Terao, Katsuyama, Fukui, 911-8601, Japan.
PLoS One. 2015 Dec 30;10(12):e0145904. doi: 10.1371/journal.pone.0145904. eCollection 2015.
A new basal hadrosauroid dinosaur from the Lower Cretaceous Khok Kruat Formation of Thailand, Sirindhorna khoratensis gen. et sp. nov is described. The new taxon is based on composite skull and mandible including premaxilla, maxilla, jugal, quadrate, braincases, predentary, dentaries, surangular, and maxillary and dentary teeth. It is diagnostic by such characters as, sagittal crest extending along entire dorsal surface of the parietal and reaching the frontoparietal suture (autapomorphy), transversely straight frontoparietal suture, caudodorsally faced supraoccipital, no participation of the supraoccipital in the foramen magnum, mesiodistally wide leaf-shaped dentary tooth with primary and secondary ridges on the lingual surface of the crown, perpendicularly-erected and large coronoid process of dentary, and nonvisible antorbital fossa of the maxilla in lateral view. Phylogenetic analysis revealed S. khoratensis as among the most basal hadrosauroids. Sirindhorna khoratensis is the best-preserved iguanodontian ornithopod in Southeast Asia and sheds new light to resolve the evolution of basal hadrosauriforms.
描述了一种来自泰国下白垩统霍克克鲁阿特组的新的基干鸭嘴龙类恐龙——呵叻诗琳通龙（Sirindhorna khoratensis），新属新种。这个新分类单元基于复合头骨和下颌骨，包括前上颌骨、上颌骨、颧骨、方骨、脑壳、前齿骨、齿骨、上隅骨以及上颌齿和齿骨齿。它的鉴别特征包括：矢状嵴沿着顶骨的整个背表面延伸并到达额顶缝（自近裔性状）；额顶缝横向笔直；枕骨在背尾方向；枕骨不参与枕大孔的构成；齿骨齿在近中远侧呈宽叶状，齿冠舌面有主嵴和副嵴；齿骨的冠状突垂直且大；侧面观上颌骨的眶前窝不可见。系统发育分析表明呵叻诗琳通龙是最基干的鸭嘴龙类之一。呵叻诗琳通龙是东南亚保存最完好的禽龙类鸟脚亚目恐龙，为解决基干鸭嘴龙形类的演化提供了新线索。
