My field and
laboratory research is focused on paleobiological and biostratigraphic questions
concerning the evolution of Mesozoic and Cenozoic terrestrial biotas. Currently I
am studying the systematic interrelationships of Mesozoic mammals, making use of
characters of both skeletal morphology and enamel microstructure. A stratigraphically
controlled series of early Paleocene (Puercan) local faunas calibrated through 40Ar/39Ar
age determinations provides the basis for analyses of the patterns and tempos of
terrestrial faunal change during the first million years after the extinctions used
to mark the end of the Cretaceous.
research projects include: an investigation of mammalian evolution across the
K/T boundary, via body size, dental morphospace, and faunal dynamics; functional analysis
of Smilodon locomotion, with emphasis on the tarsal region; analysis of
phylogenetic interrelationships of archaic ungulates; and investigations into
the biogeography of Gondwana's Cretaceous biota.