Professor of Integrative biology and a curator in the Museum of Paleontology, University of California,, Berkeley.
(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, homeothermy, and vertebrate adaptation in the early Mesozoic Era.
(4) Histology and constructional morphology of the bones of extinct reptiles. Comparative bone histology in a phylogenetic series of taxa and some ontogenetic series can provide the best picture of age, growth, and metabolism, and engineering design helps to understand functional adaptations of bone.