Tyrannosaurus rex was a huge member of a group of dinosaurs called theropods. Its name is often shortened to T. rex. Discover more in Tyrannosaurus Rex, one of the titles in the Dinosaur World series. This series helps young readers explore the different kinds of dinosaurs and other animals that lived in prehistoric times. Dinosaur World is a series of AV2 media enhanced books. A unique book code printed on page 2 unlocks your interactive eBook. These books come alive with video, audio, weblinks, slideshows, activities, and much more.