Thomas D. Carr is a vertebrate paleontologist who received his PhD 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. 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. Carr shared the Lanzendorf Prize for scientific illustration at the 2000 Society of Vertebrate Paleontology conference for the artwork in this article. In 2005, he and two colleagues described and named Appalachiosaurus, a late-surviving basal tyrannosauroid found in Alabama. He is also scientific advisor to the Dinosaur Discovery Museum in Kenosha, Wisconsin.