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首页> 外文期刊>Journal of Systematic Palaeontology >REDESCRIPTION OF THE MONGOLIAN SAUROPOD NEMEGTOSAURUS MONGOLIENSIS NOWINSKI (DlNOSAURIA: SAURISCHIA) AND COMMENTS ON LATE CRETACEOUS SAUROPOD DIVERSITY
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REDESCRIPTION OF THE MONGOLIAN SAUROPOD NEMEGTOSAURUS MONGOLIENSIS NOWINSKI (DlNOSAURIA: SAURISCHIA) AND COMMENTS ON LATE CRETACEOUS SAUROPOD DIVERSITY

机译：蒙古扁线虫蒙古沙门氏菌（DLNOSAURIA：SAURISCHIA）的重新描述以及对晚白垩世轮藻多样性的评论

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摘要

The isolated skulls of Nemegtosaurus mongoliensis and Quaesitosaurus orientalis from the Nemegt Basin of Mongolia are among the most complete sauropod cranial remains known from the Late Cretaceous, yet their evolutionary relationships to other neosauropods have remained uncertain. Redescription of the skull of Nemegtosaurus identifies key features that link it and its closely related counterpart Quaesitosaurus to titanosaur sauropods. These include a posterolaterally orientated quadrate fossa, 'rocker'-like palatobasal contact, pterygoid with reduced quadrate flange and a novel basisphenoid-quadrate contact. Other features are exclusive to Nemegtosaurus and Quaesitosaurus, such as the presence of a symphyseal eminence on the external aspect of the premaxillae, a highly vascularised tooth bearing portion of the maxilla, an enclosed 'maxillary canal', orbital ornamentation on the postorbital, prefrontal and frontal, exclusion of the squamosal from the supratemporal fenestra and dentary teeth smaller in diameter than premaxillary and maxillary teeth. Re-examination of Late Cretaceous sauropod distributions in the light of this well-supported phylogenetic hypothesis has important implications for their diversity at the end of the Mesozoic in Asia and elsewhere. Cretaceous Asian sauropod faunas consist solely of titanosauriforms, which probably migrated there from other landmasses during the Late Jurassic, during which time neosauropods were absent from Asia. Globally, narrow-crowned titanosaurs and rebbachisaurids radiated during the Cretaceous, but only titanosaurs survived into the latest Cretaceous. These late-surviving sauropods flourished on most continental landmasses until the end of the Maastrichtian.
机译：蒙古Nemegt盆地中分离出的Nemegtosaurus mongoliensis和Oriental Quaesitosaurus Orientalis的头骨是白垩纪晚期已知的最完整的蜥脚类颅骨残骸，但是它们与其他新蜥脚类动物的进化关系仍然不确定。重新命名Nemegtosaurus的头骨可识别出将其及其密切相关的Quaesitosaurus链接到Titanosaur sauropods的关键特征。这些包括后外侧定向的方形窝，“洛克人”式bas基接触，翼状翼缘减少的翼状and骨和新的类蝶骨-方形接触。其他功能是Nemegtosaurus和Quaesitosaurus所独有的，例如在前颌骨的外部存在共生突突，上颌骨高度血管化的牙齿部分，封闭的“上颌管”，眶后，前额叶和眶上的眼眶装饰额骨，上颌骨窗齿和牙齿的直径比上颌前和上颌齿小。鉴于这种系统支持的系统发育假说，对白垩纪晚期蜥脚类动物分布的重新检查对其在亚洲和其他地区中生代末期的多样性具有重要意义。亚洲白垩纪的蜥脚类动物群仅由钛龙类动物组成，它们可能在侏罗纪晚期从其他陆生动物那里迁徙到那里，在此期间，亚洲没有蜥脚类动物。在全球范围内，在白垩纪期间放射出了狭窄的冠状恐龙和雷氏龙，但只有钛恐龙幸存到了最新的白垩纪。这些幸存的蜥脚类动物在大多数大陆陆块上繁盛，直到马斯特里赫特人结束。

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