This series takes the dinosaurs living 65 million years ago as the theme, each volume takes a representative dinosaur as the main character, endows it with a unique personification personality, and tells the wonderful stories around it. In addition to fascinating stories, this series has strong knowledge, science popularization, illustrated and interesting by reducing the behaviors of predation, competition, migration, cooperation and courtship among animals in the age of dinosaurs. Each story contains different philosophies. Through the dinosaur story, it reflects the feelings of human society and inspires small readers to think about the value of life. This volume takes the Triangle dragon as the main character. A group of triangle dragons forced to migrate due to the arrival of the dry season are attacked by Tyrannosaurus Rex. Some old and weak triangle dragons choose to sacrifice themselves for the overall interests. A surviving little Triangle dragon can't bear to watch his family and companions being slaughtered, and the idea of protecting them arises. It unites each individual into a whole against Tyrannosaurus Rex. Like the arrangement of troops, it skillfully uses every force, and finally lures the Tyrannosaurus Rex into the swamp, and defeats the Tyrannosaurus Rex.