An authoritative reference guide to the animals of the prehistoric world offers a chronological study of five different geological periods, with profiles of the dinosaurs and other animals who lived during each. BOMC.,Describes the prehistoric animals that lived in various areas of the world during the different geological periods, from the Triassic through the Cretaceous.An authoritative reference guide to the animals of the prehistoric world offers a chronological study of five different geological periods, with profiles of the dinosaurs and other animals who lived during each. BOMC.,Describes the prehistoric animals that lived in various areas of the world during the different geological periods, from the Triassic through the Cretaceous.