My research uses the fossil record to understand evolutionary transitions, at the level of organisms and ecosystems. I'm interested in the origins of new kinds of organisms, such as the evolution of birds from dinosaurs and snakes from lizards, and major changes in the structure of the biosphere driven by geological events such as the Chicxulub asteroid impact that wiped out the dinosaurs.
These transitions, which created the organisms and ecosystems all around us, can only be understood with the help of the fossil record. What's more, the fossil record increasingly suggests that microevolution- the generation-to-generation changes seen today- are insufficient to explain macroevolution, because over deep time, rare processes come into play.
In recent years, I’ve studied the Cretaceous fossil record to better understand the end-Cretaceous mass extinction that wiped out the dinosaurs. Using vertebrate microfossils, it has been possible to show that not only did the asteroid wipe out the dinosaurs, it led to massive extinctions among birds, lizards, snakes, mammals and pterosaurs which drove adaptive radiations in the aftermath. Other projects focuson the origin of major groups of animals. Fossils of the primitive Cretaceous snake Tetrapodophis have helped shed light on the evolution of snakes from burrowing lizards, and a restudy of the Jurassic bird Archaeopteryx have revealed a surprisingly primitive wing structure, better suited for gliding than active flapping flight.
My goals are to continue work on the end-Cretaceous extinction event, and to launch new projects aimed at understanding vertebrate radiations and extinctions during the Cretaceous and Paleogene. I'm always happy to talk with prospective students and postdocs.