This reference work is the second supplement to Dinosaurs: The Encyclopedia (a 1998 American Library Association Outstanding Reference Book) and follows the intent and format of the encyclopedia and first supplement. In speaking of that first supplement--"superb...the scope in phenomenal"--ARBA referred to the basic volume as "a reference legend...lavishly illustrated, cleverly written, and extraordinarily comprehensive." This continuation of what is now the standard encyclopedia provides up-to-date concepts and evidence of dinosaur paleobiology and evolution. Various competing positions are well presented and exhaustively referenced. The content is based on the latest original research of paleontologists, especially in dinosaur systematics, and genera, and covers such topics as the constant changes in technology and research methods, the Mesozoic Era in general, new theoretical ideas, the dinosaur-bird debat