A new species of the sauropsid reptile Nothosaurus from the Lower Muschelkalk of the western Germanic Basin, Winterswijk, The Netherlands
A new species of the sauropsid reptile Nothosaurus from the Lower Muschelkalk of the western Germanic Basin, Winterswijk, The Netherlands
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DOI：
10.4202/app.2008.0083
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发表时间：
2009-12-01
影响因子：
1.8
通讯作者：
Albers, Paul C. H.
中科院分区：
文献类型：
--
作者：
Klein, Nicole;Albers, Paul C. H.
最近在荷兰温特斯韦克的下穆舍尔卡尔克（早期阿尼西亚）地区发现了一个只有46毫米长的虚无龙头骨，这是目前已知的最小的虚无龙头骨。它在很大程度上类似于伪龙的头骨形态。除了尺寸，直矩形和相对较宽的顶骨，上颌骨的短后部范围，头骨比例，以及上颌牙齿的总体数量较低之外，还存在差异。尽管它的尺寸很小，但头骨不能明确地解释为青少年。它显示了融合的前颌骨、鼻骨、额骨和顶骨，一个几乎共同骨化的轭骨，以及发育完全的脑组织成分，如基蝶骨和巨大的翼上骨。将该标本加入现有的系统发育分析表明，它应该被分配给一个新的物种，假龙温克尔霍斯蒂sp。至少在它的青少年身份得到明确证实之前。伪龙属（Nothosaurus winkelhorsti sp. nov.）与伪龙属（Nothosaurus juvenilis）是迄今为止最底层的伪龙。
A nothosaur skull recently discovered from the Lower Muschelkalk (early Anisian) locality of Winterswijk, The Netherlands, represents at only 46 mm in length the smallest nothosaur skull known today. It resembles largely the skull morphology of Nothosaurus marchicus. Differences concern beside the size, the straight rectangular and relative broad parietals, the short posterior extent of the maxilla, the skull proportions, and the overall low number of maxillary teeth. In spite of its small size, the skull can not unequivocally be interpreted as juvenile. It shows fused premaxillae, nasals, frontals, and parietals, a nearly co-ossified jugal, and fully developed braincase elements, such as a basisphenoid and massive epipterygoids. Adding the specimen to an existing phylogenetic analysis shows that it should be assigned to a new species, Nothosaurus winkelhorsti sp. nov., at least until its juvenile status can be unequivocally verified. Nothosaurus winkelhorsti sp. nov. represents, together with Nothosaurus juvenilis, the most basal nothosaur, so far.