Thomas D. Carr is a vertebrate paleontologist who received his Ph.D. from the University of Toronto in 2005. He is now a member of the biology faculty at Carthage College in Kenosha, Wisconsin. Much of his work centers on tyrannosauroid dinosaurs.^[1] Carr published the first quantitative analysis of tyrannosaurid ontogeny in 1999, establishing that several previously-recognized genera and species of tyrannosaurids were in fact juveniles of other recognized taxa.^[2] Carr shared the Lanzendorf Prize for scientific illustration at the 2000 Society of Vertebrate Paleontology conference for the artwork in this article.^[3] In 2005, he and two colleagues described and named Appalachiosaurus, a late-surviving basal tyrannosauroid found in Alabama.^[4]