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

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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.