Mark Webster Assistant Professor, Department of the Geophysical Sciences and the College Department of the Geophysical Sciences 5734 S. Ellis Ave. HGS 233 Chicago, IL 60637 USA Phone: 773/702-4071 E-mail: mwebster@geosci.uchicago.edu Publications

Mark Webster studies the ontogenetic development, morphology, and morphological variability of trilobite species in order to understand the paleobiology and evolutionary history of these organisms in unparalleled detail. As part of the specimen-based research in his lab, geometric morphometric analyses are employed to rigorously quantify patterns of ontogenetic and evolutionary shape change, and cladistic methods are used to hypothesize evolutionary relationships among taxa. Field geology is a major component of Mark's work: several trips are made each year to make new fossil collections at very fine stratigraphic resolution in Cambrian outcrops in the western United States. Sequence stratigraphic and sedimentological data amassed in the field allow the collections to be placed into a paleoenvironmental framework. Together with the developmental data, this approach provides insight into the mechanisms of and the driving forces behind evolutionary change in the trilobites. Current research projects include resolving the early evolutionary history of the Trilobita (in particular the basal redlichiids), refining the Lower and Middle Cambrian biostratigraphic zonation of Laurentia, and using studies of trilobite morphological variability (partitioned into phylogenetic, geographic, and temporal components) to uncover patterns and potential constraints in the evolution of the group, which may provide novel insight into the nature of the Cambrian explosion in the diversity of life.

Education:

• Ph.D., University of California, Riverside, 2003