PhD Dissertation Defense - Edward Daniel Medeiros - Environmental Science and Policy

PhD Dissertation
Department of Environmental Science and Policy
College of Science
George Mason University

Candidate: Edward Daniel Medeiros
Defense Date and Time: May 12, 2026 at 9:00am
Defense Location: Exploratory Hall, Room 1309 and on Zoom
Title: Abandoning Land: Functional Morphology of Archaeocete Cetaceans and Implications for the Development of Cenozoic Marine Ecosystems

Dissertation Director: Dr. Mark D. Uhen
Committee: Dr. Geoffrey Gilleaudeau, Dr. Brittany Hupp, Dr. T. Reid Nelson

ABSTRACT

Over tens of millions of years, cetaceans have undergone a dramatic evolutionary change from relatively small-bodied, dominantly terrestrial animals into a broad diversity of obligate aquatic forms which play significant roles in marine ecosystems. This dissertation: 1) examines the evolution of cetacean limbs in the earliest forms in an effort to understand how semiaquatic cetaceans may have moved on land; 2) evaluates potential swimming modality and proposes a novel lifestyle for the giant predatory Eocene cetacean, Basilosaurus; 3) examines patterns of habitat preference in marine mammal fossils throughout the Cenozoic and how they may relate to diversification within groups.