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种活着的物种，占所有活着的脊椎动物的一半以上--出现在世界历史上的关键时期。哪些因素，如环境条件或动物的生物学特征，可能推动了这些血统的进化和适应性辐射，目前仍存在争议。我的实验室专注于这些鱼类的起源、进化和生物地理，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。在晚白垩世(~90mya)，大陆的排列留下了许多浅海航道，为鱼类提供了理想的海洋栖息地，而在新生代，随着大陆裂谷和陆块的碰撞，淡水发生了重大重组。白垩纪海洋研究的重点是北美和摩洛哥的动物群，分别代表西部内海和特提斯海，前者是一大片水域，将北美东部和西部从墨西哥湾延伸到北冰洋，后者大致将非洲和欧亚大陆隔开，经常穿过北非延伸到分隔西非和大陆其他地区的大西洋。要研究的新生代淡水动物群来自非洲和亚洲；到始新世(~55-33英里)，大陆更接近它们的现代位置，印度孤立但向北向亚洲移动，裂谷尚未将沙特阿拉伯与非洲广泛分开。到中新世(~23万年)，非洲通过阿拉伯板块与欧洲接触。我实验室的项目主要集中在加拿大和摩洛哥的白垩纪沉积，北美的新生代沉积，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中采集的鱼类化石。目标是通过描述发现的新物种，确定这些物种的进化关系，并利用鱼类的关系来表明它们所来自的水体之间的生物地理关系，来描述这些动物群的特征。

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.