内蒙古上白垩统窃蛋龙科一新属种及其地层学意义(英文)

记述了一件发现于内蒙古临河巴彦满达呼上白垩统乌兰苏海组的窃蛋龙科新材料并建立了一新属新种——戈壁乌拉特龙(Wulatelong gobiensis gen. et sp. nov.)。新属种具有以下不同于其他窃蛋龙科成员的独特特征:外鼻孔大而细长,腹端低于前上颌骨中部;上颌骨的颧骨支呈带状,并向后延伸至眶前隔之后,叠覆于颧骨外侧面;外侧视,上隅骨的前背突基部收缩。戈壁乌拉特龙具有一些其他窃蛋龙科成员不具有的近祖特征,而与更原始的窃蛋龙类接近,说明戈壁乌拉特龙代表了窃蛋龙科中一个相对原始的属种。这些近祖特征包括:下颞颥孔的背缘较窄,泪骨的前突和后突相对较长,外翼骨和外下颌孔的位置都相对靠后,肩胛骨短而纤细,肠骨的耻骨茎较坐骨茎向腹侧延伸更长并前后向更宽,坐骨较短,以及第三跖骨近端侧扁等。因此戈壁乌拉特龙的系统发育位置可能居于原始窃蛋龙类和其他窃蛋龙科成员之间。对巴彦满达呼恐龙动物群的初步分析支持巴彦满达呼红层代表了蒙古高原戈壁地区上白垩统红层中的最早沉积层位的结论。

A new oviraptorid from the Upper Cretaceous of Nei Mongol,China, and its stratigraphic implications

Here we report a new oviraptorid taxon based on a specimen collected from the Upper Cretaceous Wulansuhai Formation of Bayan Mandahu, Linhe, China. This new taxon is distinguishable from other oviraptorid species by the following unique features: the ventral extremity of the large and elongate external naris is located below the mid-height of the premaxilla, the strap-like jugal process of the maxilla extends well beyond the preorbital bar posteriorly and overlaps the jugal, and the anterodorsal process of the surangular is basally constricted in lateral view. Although diagnosable as an oviraptorid, this new taxon possesses several plesiomorphic features absent in other oviraptorids but reminiscent of more basal oviraptorosaurs, suggesting a relatively basal position within the Oviraptoridae. The infratemporal fenestra has a narrow dorsal border, the anterior and posterior processes of the lacrimal are relatively long, the ectopterygoid is located relatively posteriorly, the external mandibular fenestra is comparatively posterior in position, the scapula is relatively short and slender, the pubic peduncle of the ilium is both more ventrally extended and much wider anteroposteriorly than the ischial peduncle, the ischium is relatively short, and metatarsal III is compressed between metatarsals II and IV. This taxon, Wulatelong gobiensis gen. et sp. nov., is therefore inferred to be a basal oviraptorid. A preliminary analysis of the Bayan Mandahu dinosaur fauna supports the view that the Bayan Mandahu strata are the oldest Upper Cretaceous red beds exposed in the Gobi area of the Mongolian Plateau.