This post has been circulating among nerds today, and it’s a really great one. It’s written by Thomas Holtz, a world-renowned expert on tyrannosaurids, and was first posted on the Dinosaur Mailing List in response to a question. A number of other blogs have reprinted it, so if you want to read it (you really should) go to Archosaur Musings or Sauropod Vertebrae Picture of the Week. I was lucky enough to take a class from Dr. Holtz in one of my post-bacc semesters at the University of Maryland and he is one of those great professors who happen to be both extremely knowledgable and an excellent communicator. This is a must-read.