Systematic Study of Late Cretaceous Lizards from the Mongolian Gobi Desert

9806811高，晚白垩世是大多数现存蜥蜴支系建立和早期分化的关键时期。蒙古戈壁沙漠是这一时期蜥蜴化石的主要来源。蒙古科学院-美国自然历史博物馆从戈壁探险收集的大量化石为开展拟议的项目提供了核心材料。该藏品包括大约700个保存异常完好的与下颌关节相连的头骨；一些是颅后骨骼。这份材料记载了4个较高类群的约30个分类单元，其中至少有11个新分类单元需要描述。由于标本中包含了各种现代蜥蜴支系在系统发育上的重要基础类群，对这些化石的研究将极大地提高对蜥蜴系统发育的认识，并为更好地评价晚白垩世主要蜥蜴类群的繁殖提供了很大的希望。以前对戈壁沙漠晚白垩世蜥蜴的研究揭示了严重的分类学和系统发育问题。许多在系统发育上重要的分类群描述不充分或不正确，由于错误描述解剖结构或曲解相关分类群之间的关系而产生的问题亟需解决。拟议的研究包括对鲜为人知的分类群进行主要的分类修订，以澄清它们的解剖学细节，并对它们的关系提供忠实的评估。将对选定的蜥蜴分类群进行全面的分支分析。这些分析将包括戈壁样本中各种分支的重要基本成员，并将纳入以前关于现存蜥蜴分支的工作数据。这项研究承诺澄清戈壁蜥蜴现有的混沌分类，并根据恢复的戈壁和相关类群的系统发育关系提供明确的分类方案。

9806811 Gao The Late Cretaceous is a crucial interval for the establishment and early diversification of most extant lizard clades. The Mongolian Gobi Desert is a major source of fossil lizards of this age. A large fossil collection amassed by the Mongolian Academy of Sciences-American Museum of Natural History Expeditions from the Gobi provides the core material for undertaking the proposed project. The collection consists of some 700 exceptionally well-preserved skulls in articulation with mandibles; some with postcranial skeletons. This material documents some 30 taxa in four higher groups, among which at least 11 new taxa need to be described. As the samples include phylogenetically important basal taxa of various modern lizard clades, study of these fossils will substantially improve knowledge of lizard phylogeny, and holds great promise for better appreciation of the Late Cretaceous proliferation of the major lizard groups. Previous studies of Late Cretaceous lizards from the Gobi Desert reveal serious taxonomic and phylogenetic problems. Many phylogenetically important taxa were inadequately or incorrectly described, and the problems stemming from misdescription of anatomical structures or misinterpretation of relationships of the relevant taxa badly need to be resolved. The proposed study includes major taxonomic revision of the poorly understood taxa, in order to clarify specifics of their anatomy and to provide faithful assessment of their relationships. Comprehensive cladistic analyses of selected lizard taxa will be conducted. These analyses will include important basal members of various clades from the Gobi sample and will incorporate data from previous work on extant lizard clades. The proposed study promises to clarify the existing chaotic classification of the Gobi lizards and provides an explicit classification scheme on the basis of recovered phylogenetic relationships of Gobi and related taxa.