Abstract: The dromaeosaurid Linheraptor exquisitus was named in 2010 based on a nearly complete skeleton recovered from the Upper Cretaceous Wulansuhai Formation at the Gate Locality, in Bayan Mandahu, western Nei Mongol, China. However, three recent studies regarded L. exquisitus as a subjective junior synonym of Tsaagan mangas, a dromaeosaurid from the Upper Cretaceous Djadokhta Formation of the Ukhaa Tolgod locality, Mongolia.Here we refute this synonymy based on 61 morphological features that distinguish L. exquisitus from T. mangas. Many of these features are based on new observations from previously unprepared areas of the L. exquisitus holotype, most notably from the left lateral side of the skull. These observations underscore and strengthen our original taxonomic separation of L. exquisitus and T.mangas. Evidence from L. exquisitus points to an unexpectedly complex distribution of derived osteological features amongst dromaeosaurids, because this species possesses features that were previously identified as autapomorphies of T. mangas or indeed of various other dromaeosaurids. Our review demonstrates that the proposed synonymy between L. exquisitus and T. mangas ignores many subtle morphological variations. Increased taxonomic sampling breaks down seemingly obvious diagnostic differences into more subtle morphological variations, which are potentially of great importance for fine-scale phylogenetic analyses. Rigorous quantitative methods using continuous data represent a promising way to exploit this type of information in future systematic studies.

摘要： 驰龙类的精美临河盗龙(Linheraptor exquisitus)于2010年基于一件近完整骨架命名，化石采自内蒙古西部巴彦满达呼大门地点上白垩统乌兰苏海组。然而，最近三项研究认为精美临河盗龙是蒙古乌哈托喀地点上白垩统捷达克赫塔组发现的白魔龙(Tsaagan mangas)的晚出异名。本文依据61个形态学特征区分精美临河盗龙和白魔龙，否认了上述观点。许多特征来自对精美临河盗龙正型标本先前未修理部分，特别是头骨左侧的观察。这些新观察支持和加强了我们先前认为的精美临河盗龙和白魔龙属于两个不同属种的观点。精美临河盗龙具有的一些特征之前被认为是白魔龙或者其他驰龙类的自近裔特征，这表明进步的骨骼特征在驰龙类中的分布异常复杂。认为精美临河盗龙和白魔龙为同物异名的观点实际上忽略了很多微小的形态变异。增加分类取样可以将那些看似显著的鉴定特征转化为更加细微的形态变异，而这些形态变异对于精细的系统发育分析具有潜在的重要意义。在未来的研究中，利用连续数据的严格定量方法，有助于处理类似信息。