Survived in the late Jurassic. The individual is large, with a body length of 22 meters, a height of 3.5 meters and a weight of 45 tons. It is the largest dinosaur in Asia. Small head, big eyes, long nostrils on the top of the head, suitable for life in water. The neck is tall, the spine is thick, and the joints of the limbs are rough. The teeth are slender and nail-shaped, indicating that they are herbivores. They move slowly and are often killed by carnivorous dinosaurs, hiding in the water to avoid the enemy. In water, buoyancy can be used to reduce the weight burden of limbs, and aquatic plants can also be obtained as food. Fossils were first discovered in Hechuan County, Sichuan Province, China. The Beijing Museum of Natural History exhibited its skeleton fossils.