Dr. Norell works in several areas of specimen-based and theoretical research. He works on the description and relationships of coelurosaurs and studies elements of the Asian Mesozoic fauna. He analyzes important new "feathered" dinosaurs from Liaoning, China, and develops theoretical methods for better understanding phylogenetic relationships and pattern in the fossil record. Under his co-direction with Michael Novacek, a team of paleontologists working in the Gobi desert since 1990 has produced a wealth of great specimens. This has led to the development of a new phylogenetic hypothesis for coelurosaurian theropods. Similar studies have been carried out on fossil lizards and champsosaurs from this region. Work on these animals has led Dr. Norell's team to discover some aspects of anguimorph phylogeny, to recognize new clades of lizards, to phylogenetically place problematic taxa, and to describe poorly known taxa based on new material. Dr. Norell's theoretical work focuses on developing methodology for evaluating the effect of missing data on large data sets, sensitivity methods for character weighting, and using phylogeny to estimate patterns in the fossil record such as diversity and extinction. He also studies the relationship between stratigraphic position and phylogenetic topology.