Vertebrate paleontologist and evolutionary biologist studying the evolution of major lineages of terrestrial vertebrates (especially dinosaurs and mammals), with a particular focus on variation within species, which is the raw material for evolutionary change. Recent research successes include naming the dromaeosaurid ('raptor') dinosaur Kuru kulla, discovering that a major transformation in the evolution of the bird wing actually occurred in bird-like theropod dinosaurs, and proving that Nanotyrannus was a valid dinosaur species, not the juvenile form of T. rex like many paleontologists thought for decades.
