150 million years ago in the Gobi Desert, there were many different types of dinosaurs. Some dinosaurs were very large and heavy, while others were smaller. Some dinosaurs were meat-eaters that hunted other animals, while others were plant-eaters. Students read texts describing three different dinosaur species: Tyrannosaurus, Gallimimus, and Compsosnathus. The texts provide details about when and where each dinosaur lived, its physical characteristics, and whether it was a meat-eater or plant-eater.