Mesozoic neoselachians (Chondrichthyes, Elasmobranchii): Patterns of phylogeny, biogeography and diversity in a changing world

现代新塞拉基亚动物是一个定义明确的群体，包括所有的鲨鱼、鳐鱼和鳐鱼。它们通过骨骼的突触连接在一起。相反，新塞拉基亚化石主要是通过它们的牙齿来识别的，因为保存下来的软骨骨骼是化石记录中的例外。因此，许多（如果不是大多数的话）新塞拉亚化石的分类是模糊的。从早三叠纪到晚白垩纪的几个地方都发现了中生代新塞拉基亚动物的骨骼遗骸。这些标本对于了解新塞拉亚动物的早期进化和多样化至关重要。在这个项目的框架内，所有这些标本都被检查、分析，并与现存的分类群进行了比较。化石和现存动物的相互关系将用现代系统发育方法加以仔细研究。化石分类群的多样性和古生物地理关系将在系统发育分析和相似性测量的基础上进行重建。此外，利用分子序列重建了现代新塞拉基亚动物的相互关系。所有的分析结果进行比较和结合，以建立一个全面的假设新塞拉基亚进化，多样化和相互关系。仅以牙齿为基础的分类群的可靠性还有待商榷。

Modern neoselachians are a well-defined group including all sharks, skates, and rays. They are united by synapomorphies of the skeleton. Conversely, fossil neoselachians are recognized primarily by their teeth since the preservation of the cartilaginous skeleton is the exception in the fossil record. Consequently, the taxonomy of many if not most fossil neoselachians is obscure. Skeletal remains of Mesozoic neoselachians are known from several localities ranging from the Early Triassic to the Late Cretaceous. These specimens are essential for understanding the early evolution and diversification of neoselachians. In the framework of the project, all these specimens are examined, analysed, and revised in comparison with extant taxa. The interrelationshipsof fossil and extant will be scrutinized using modern phylogenetic methods. The diversity and palaeobiogeographic relationships of fossil taxa will be recontructed based on phylogenetic analyses but also using similarity measurements. In addition, the interrelationships of modern neoselachians are recontructed using molecular sequences. The results of all analyses are compared and combined to estabish a comprehensive hypothesis of neoselachian evolution, diversification, and interrelationships. The reliability of taxa based on teeth alone will be debated.