DISSERTATION RESEARCH: The Evolution of Specialized Teeth and Jaws in Early Mesozoic Ray-Finned Fishes and Their Impact on Widespread Niche Differentiation

点击翻译按钮获取中文摘要

The ray-finned fishes (e.g., trout, clownfish, seahorse, bass) are the most diverse group of vertebrates on Earth today and display a vast array of physical differences with regard to body shape, skull and jaw morphology, and tooth specializations. Ray-finned fishes have a long evolutionary history, and this study focuses on two extinct groups of fishes that lived during the Early Mesozoic (250-190 million years ago): the disc-shaped, deep-bodied dapediids and the torpedo-shaped, primitive redfieldiids. These two groups of fishes provide an ideal contrast (e.g., deep body versus narrow body, differences in jaws) for testing hypotheses of the impact of specialization of tooth and jaw anatomy and morphology. The researches will compare this body shape contrast with the diet, habitat preference, behavior, and niche specialization of the fish. The project will study fossils from the Early Mesozoic, a volatile time in Earth's history with global tectonic events changing the geography of the planet and shaping the diversity of organisms in different ecosystems. This research will increase our understanding of how these two groups of extinct fishes have adapted to occupy different ecological spaces and exploit different food sources. The research will utilize state-of-the-art two- and three-dimensional digital imaging techniques, such as micro-computed tomography (CT) scanning. These tools will measure jaw and cranial anatomy and morphology as well as tooth microwear, in well-preserved redfieldiid and dapediid fossils. Using these data the investigators of this project will be able to address hypotheses about how tooth and jaw morphology relate to ecological niche space and evolutionary history. This project will provide graduate and undergraduate training in morphological and morphometric techniques, and data obtained from this study will be catalogued in online data repositories.