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

现代的新剑鱼是一个定义明确的群体，包括所有的鲨鱼、鳐和鳐。它们通过骨骼的突触形态结合在一起。相反，新塞拉契亚人化石主要是通过他们的牙齿来识别的，因为软骨骨骼的保存是化石记录中的例外。因此，许多（如果不是大多数的话）新塞拉契亚人化石的分类是模糊的。从早三叠世到晚白垩世的几个地区都发现了中生代新塞拉契人的骨骼化石。这些标本对于了解新塞拉动物的早期进化和多样化至关重要。在该项目的框架内，所有这些标本进行检查，分析，并与现存分类群进行比较修订。化石和现存的相互关系将用现代系统发育学方法来仔细研究。化石分类群的多样性和古生物地理关系将根据系统发育分析重建，但也使用相似性测量。此外，现代新塞拉人的相互关系重建使用分子序列。所有分析的结果进行比较，并结合起来，建立一个全面的假设新塞拉奇进化，多样化，和相互关系。仅基于牙齿的分类群的可靠性将被辩论。

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.