Stephen Dornbos

Assistant Professor

372 Lapham Hall
(414) 229-6630
sdornbos@uwm.edu

PhD University of Southern California
MS University of Southern California
BA College of Wooster

Specializations: Evolutionary Paleoecology, Paleobiology

Research:

My field of research is the evolutionary paleoecology of marine invertebrates. Within this broad field, I am primarily interested in the paleoecology, evolution, and taphonomy of early animals during the Neoproterozoic and Cambrian. This interest is currently expressed in three heavily field-based research avenues:  

Paleoecology and Environmental Setting of the Early Cambrian Chengjiang Fauna: The soft-bodied Early Cambrian Chengjiang fauna of southwest China provides an unparalleled view of animal life during the heart of the Cambrian radiation. My research combines detailed examination of the rocks in which the Chengjiang fossils are preserved with analysis of their functional morphology in order to learn more about the paleoecology of benthic animals during this critical time interval. The results of this research have important implications for the early evolution of animals, as the ecologic interactions amongst animals and between them and their environment were certainly crucial in fueling what is popularly known as the "Cambrian explosion."  

Evolutionary Paleoecology of Early Echinoderms: Many Cambrian echinoderms are known for their unusual morphologies when compared to later-Paleozoic and modern echinoderms. This observation has often led to their interpretation as early evolutionary "experiments." Through careful examination of the rocks in which these early echinoderms are preserved, often located in the Great Basin of the western U.S. , as well as analysis of their substrate adaptations, my research provides new insight into their paleoecology. Results of this research indicate that many early echinoderms probably have unusual morphologies in part because they were adapted to non-actualistic substrate conditions that no longer exist in similar environments today, not because they were early evolutionary "experiments." This adaptation to non-actualistic substrates was probably also common in other groups of Cambrian benthic animals, and so may partially explain many of their unusual morphologies as well.  

Taphonomy of Phosphatized Neoproterozoic Animal Embryos: The phosphatized animal embryos preserved in the phosphorites of the Neoproterozoic Doushantuo Formation of southwest China currently provide the earliest unambiguous fossil evidence for animals. My research utilizes field observations, petrography, and specimen-based studies to understand the taphonomic processes that led to the preservation of these spectacular fossils, as well as the taphonomic biases of the Doushantuo phosphorites. This work is part of a larger collaborative effort that includes biologists, paleontologists, and geochemists from China , Taiwan , and the United States . The goal of this collaboration is to achieve a thorough understanding of the fossil content, geochemistry, paleoenvironmental setting, and taphonomy of the Doushantuo Formation phosphorites.

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