In the late Jurassic, the dinosaurs in what is now Sichuan Province, China ushered in a golden age of development. Both species and numbers of dinosaurs had increased considerably. Among numerous groups, sauropod dinosaurs had seen especially rapid development. The novel tells the story of a Mamenchisauru named Er Ma in the sauropod dinosaur family. Abandoned by his parents, he misidentified a Tuojiangosauru named Qi Chuan as his father. Since then on, Er Ma and Qi Chuan had experienced a lot of fun things together. The true feelings between them was really moving.