Taxonomy, phylogeny, palaeobiology, and taphonomy of the Pachypleurosauria (Reptilia: Sauropterygia) from the Lower Muschelkalk of Winterswijk, NL

荷兰东部的Winterswijk采石场（下Muschelkalk）可能是当今最有趣的Muschelkalk露头，就脊椎动物化石而言。除了陆地爬行动物非常常见且保存完好的足迹和轨道外，它还产生了越来越多的海洋爬行动物的部分关节骨骼，特别是蜥脚类（厚肋龙和假龙）。这些形式仅在其他Muschelkalk露头的孤立骨骼中发现。目前的项目，这是一个更大的荷兰和德国的联合努力的一部分，将集中在pachypleurosaurs，最丰富的脊椎动物身体化石在温特斯韦克。温特斯韦克厚肋龙类特别令人感兴趣，因为它们的地质出现较早，而且它们提供了丰富的资料，否则鲜为人知的分类群。具体来说，我们想弄清楚目前可能存在的两种厚肋龙（Anarosaurus heterodontus和Dactusaurus sp.）的形态和阿尔法分类，将它们放入系统发育框架，研究它们的个体发育，它们的生活史（使用骨组织学），最终研究它们和整个群体的进化。该项目的最后一个方面将是假设的制定和测试，以解释Winterswijk采石场极不寻常的埋藏学。

The Winterswijk quarry (Lower Muschelkalk) in the eastern Netherlands is probably the most interesting Muschelkalk outcrop today, as far as vertebrate fossils are concerned. In addition to the extremely common and well preserved tracks and trackways of terrestrial reptiles, it is yielding an ever increasing amount of partially articulated skeletons of marine reptiles, in particular sauropterygians (pachypleurosaurs and nothosaurs). These forms are known from isolated bones only in other Muschelkalk outcrops. The current project, which is part of a larger Dutch-German joint effort, will focus on the pachypleurosaurs, the most abundant vertebrate body fossils in Winterswijk. The Winterswijk pachypleurosaurs are of particular interest because of their early geological occurrence and because they provide abundant material of otherwise poorly known taxa. Specifically, we want to work out the morphology and alpha taxonomy of the probably two species of pachypleurosaurs present (Anarosaurus heterodontus and Dactylosaurus sp.), put them into a phylogenetic framework, study their ontogeny, their life history (using bone histology), and ultimately their evolution and that of the entire group. The final aspect of the project will be the formulation and testing of hypothesis to explain the highly unusual taphonomy of the Winterswijk quarry.