Thomas Holtz is an American paleontologist specialising in theropods (especially Tyrannosaurus rex); how they evolved, how they moved, how they are categorised, and how separate species evolve in similar ways due to factors such as geography. He is currently the Principal Lecturer, Department of Geology, at the University of Maryland (USA).
He obtained his bachelors degree from Johns Hopkins University (Baltimore, Maryland, USA) in 1987, and earned his Masters degrees and PhD from Yale University (New Haven, Connecticut, USA) in 1990 and 1992.
Thomas has helped write numerous books and scientific papers, and has also appeared in multiple dinosaur-related documentaries. He is also one of the key researchers who proved that tyrannosaurs are not carnosaurs (but instead coelurosaurs).
When you want to dig for dino data!