A new Middle Triassic arboreal reptile fauna from the Voltziensandstein (Grès à Voltzia) and the recovery of forest ecosystems

三叠纪是生命进化的一个重要阶段，全球生态系统在二叠-三叠纪灭绝后逐渐恢复。在这段时间里，爬行动物在海洋、淡水和陆地环境中经历了重大的进化辐射。最不为人所知的陆地群落之一是森林生态系统，这些生态系统在中三叠世早期缓慢重建。阿尔萨斯（法国）的Voltziensandstein（Grès à Voltzia）是保护这种生态系统的一套特殊的动物园。这个岩石序列产生了丰富的植物区系，不同的节肢动物和鱼类动物群，以及两个未描述的爬行动物类群收集的路易斯Grauvogel在世纪。后者之一，分类群A，目前有83个标本，包括两个关节骨骼保存完好的头骨材料。这种15厘米长的双壳爬行动物保留了被认为与树栖攀爬相关的四肢特征，骨骼保留了广泛的表皮结构。这些包括硬化的表皮结构，可能被解释为显示功能或滑翔或飞行器的组件。设想的项目侧重于Grès à Voltzia的爬行动物，它们的解剖学和系统发育位置，生活方式以及森林栖息地内的生态关系。它整合了以下数据：（1）新爬行动物分类群A和B的形态，（2）它们出现的地点，（3）这些地方保存丰富的植物群和鱼类，软体动物和节肢动物群，以了解这些极不寻常的森林爬行动物与它们生活的古生态环境之间的相互作用。这需要对Grauvogel在Grès à Voltzia上收集的现有数据进行详细分析和一些新的获取。该项目的主要目标是（1）记录新爬行动物分类群A和B的形态（包括CT数据），（2）阐明它们的系统发育位置，（3）检查这些分类群中的攀援适应，（4）研究这些爬行动物的生境和假定的生态特征，最后（5）分析表皮和骨骼结构的功能，以便在两种相互竞争的假设之间做出决定：（a）空中滑翔机制或（B）精心制作的展示结构。

The Triassic was an important phase for the evolution of life, within which a gradual recovery of the global ecosystems after the Permian-Triassic extinction took place. During this time interval, reptiles experienced major evolutionary radiations in marine, freshwater, and terrestrial environments. One of the least understood terrestrial communities were those of forest ecosystems, which were slowly re-established by early Middle Triassic time. An exceptional suite of fossillagerstätten preserving such ecosystems is the Voltziensandstein (Grès à Voltzia) of Alsace (France). This rock sequence yielded rich floras, diverse arthropod and fish faunas, and two undescribed reptile taxa collected by Louis Grauvogel in the 20th century. One of the latter, taxon A, is present with 83 specimens, including two articulated skeletons with well-preserved skull material. This 15 cm long diapsid reptile preserves features in the limbs that are believed to correlate with arboreal climbing, and the skeletons preserve extensive integumentary structures. These include stiffened epidermal structures that might be interpreted as either display features or components of a gliding or flying apparatus.The envisioned project focuses on the reptiles of the Grès à Voltzia, their anatomy and phylogenetic position, mode of life, and ecological relations within the forest habitat. It integrates data on (1) the morphology of the new reptile taxa A and B, (2) the fossillagerstätten at which they occur, and (3) the preserved rich flora and fish, mollusc and arthropod fauna of these localities in order to understand the interactions between these highly unusual forest-dwelling reptiles and the paleoecological context in which they lived. This requires a detailed analysis and some new acquisition of the available data on the Grauvogel collection on the Grès à Voltzia. Principal goals of the project are (1) to document the morphology of the new reptile taxa A and B (including CT data), (2) elucidate their phylogenetic position, (3) examine the climbing adaptations in these taxa, (4) study the habitat and putative ecological traits of these reptiles and finally (5) analyze the function of the integumentary and skeletal structures in order to decide between the two competing hypotheses: (a) an aerial gliding mechanism or (b) an elaborate display structure.