Palaeontology of freshwater and marine fishes: Evolution of the modern faunas

现代鱼类的巨大多样性——超过29,000种现存物种，超过所有现存脊椎动物的一半——出现在世界历史的关键时期。哪些因素，如环境条件或动物的生物特征，可能推动了这些谱系的进化和适应性辐射，仍然存在争议。我的实验室专注于这些鱼类的起源、进化和生物地理学，以阐明现代谱系的起源和进化。一些关键的谱系出现在白垩纪的海水中，而另一些则出现在后来的淡水中。在晚白垩纪（~ 90mya），大陆的排列留下了许多浅海，为鱼类提供了理想的海洋栖息地，而在新生代，淡水经历了大陆裂谷和陆地块碰撞的重大重组。白垩纪海洋研究的重点是来自北美和摩洛哥的动物群，分别代表西部内陆海道和特提斯海，西部内陆海道是分隔北美东部和西部的大片水域，从墨西哥湾一直延伸到北冰洋，特提斯海大致将非洲和欧亚大陆分开，通常穿过北非到达大西洋，将西非与非洲大陆的其他部分分开。研究的新生代淡水动物群主要来自非洲和亚洲；到始新世（距今55-33万年），大陆更接近于它们现在的位置，印度是孤立的，但向北移动到亚洲，而沙特阿拉伯和非洲之间还没有广泛分离。到中新世（~ 23mya），非洲通过阿拉伯板块与欧洲接触。我实验室的项目集中在加拿大和摩洛哥的白垩纪沉积物，北美的新生代沉积物，以及中国、巴基斯坦、埃及、东非和印度尼西亚的始新世和更年轻的沉积物中收集的化石鱼类。目标是通过描述新发现的物种，确定这些物种的进化关系，并利用鱼类的关系来指示它们来自的水体之间的生物地理关系，来描述动物群的特征。

The vast diversity of modern fishes - over 29,000 living species, more than half of all living vertebrates - arose during key periods in the history of the world. What factors, such as environmental conditions or biological characteristics of the animals, might have driven the evolution and adaptive radiation of these lineages are still debated. My lab focusses on the origin, evolution, and biogeography of these fishes, to elucidate the origins and evolution of the modern lineages. Some key lineages arose in marine waters in the Cretaceous, while others arose later in fresh waters. During the Late Cretaceous (~ 90 mya), the arrangement of the continents left a number of shallow seaways that provided ideal marine habitats for fish, while in the Cenozoic, fresh waters underwent major reorganizations with continental rifting and collision of land masses. The Cretaceous marine studies focus on faunas from North America and Morocco, respectively representing the Western Interior Seaway, a large body of water separating eastern and western parts of North America stretching from the Gulf of Mexico to the Arctic Ocean, and the Tethys Sea, roughly separating Africa and Eurasia and often reaching across northern Africa to the Atlantic Ocean separating West Africa from the rest of the continent. Cenozoic freshwater faunas to be studied are those from Africa and Asia; by the Eocene (~ 55-33 mya), the continents were closer to their modern positions, with India isolated but moving north towards Asia, and rifting not yet broadly separating Saudi Arabia from Africa. By the Miocene (~23 mya) Africa was in contact with Europe through the Arabian plate. Projects in my lab concentrate on fossil fishes collected from Cretaceous deposits of Canada and Morocco, Cenozoic deposits of North America, and Eocene and younger deposits of China, Pakistan, Egypt, East Africa, and Indonesia. The goals are to characterize the faunas by describing the new species found, determining the evolutionary relationships of those species, and using the relationships of the fishes to indicate biogeographic relationships among the water bodies from which they came.