My work falls into four general areas: (1) Origin of major evolutionary adaptations. Through a synthesis of phylogenetic, functional, and comparative morphological evidence, I try to assemble the best-supported evolutionary sequences available and to reconstruct the steps by which major adaptations, particularly flight, arise. (2) The beginning of the "Age of Dinosaurs." Although I work generally on Mesozoic vertebrate paleontology, I am most interested in the changes in the terrestrial vertebrate fauna that took place around the Triassic-Jurassic boundary. (3) Systematics, functional morphology, and flight of pterosaurs. Pterosaurs, the first vertebrates to gain powered flight, provide many interesting keys to the evolution of posture, locomotion, homeothemy, and vertebrate adaptation in the early Mesozoic Era. (4) Histology and constructional morphology of the bones of extinct reptiles. We study the microscopic structure of bones, and place our data in two contexts: phylogenetic (evolution of tissue types) and ontogenetic (development of tissue types with age). These two approaches, taken together, can provide the best picture of age, growth, and metabolism, and engineering design of bone. Our histology work is in conjunction with other researchers in California, Montana, and France.
Research Expertise and Interest
evolutionary biology, paleontology, systematics, functional morphology, Mesozoic vertebrate paleontology, terrestrial vertebrate fauna, pterosaurs, Mesozoic era, bones of extinct reptiles