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）可能是今天最有趣的Muschelkalk露头，就脊椎动物化石而言。除了极为常见且保存完好的陆生爬行动物的足迹和轨迹外，它还发现了越来越多的海洋爬行动物的部分关节骨骼，特别是龙类动物（厚胸膜龙和无龙）。这些形式只在Muschelkalk其他露头的孤立骨骼中被发现。目前的项目是荷兰和德国联合开展的一个大型项目的一部分，将重点研究肿胸膜龙，这是温特斯韦克最丰富的脊椎动物身体化石。温特斯韦克厚胸膜龙之所以引起人们的特别兴趣，是因为它们的地质年代较早，而且它们提供了大量其他鲜为人知的分类群的材料。具体来说，我们想要研究现存的两种肿胸膜龙（异齿龙和Dactylosaurus sp.）的形态和α分类学，将它们纳入系统发育框架，研究它们的个体发育，它们的生活史（使用骨骼组织学），最终研究它们和整个类群的进化。该项目的最后一个方面将是制定和测试假设，以解释Winterswijk采石场极不寻常的地学。

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.