Chongqing, a municipality on the middle and upper reaches of the Yangtze River, enjoys the reputation of "the city built on the back of dinosaur". Quite a few dinosaur fossils preserved in good condition and having important value for scientific research were found here.

  Mamenchisaurus hochuanensis    

Mamenchisaurus hochuanensis, discovered hereabout in 1959, was a species living in the late stage of Jurassic period 130 million years ago. It was 22 meters in length, 3.5 meters in height, and up to 3.5 tons in weight. Its neck was 9 meters long, enabling the head to extend into the window on the third floor. Its mighty shoulder harness not only firmly connected forelimbs and body, but also abated the shock generated by forelimbs when stamping on the field. With solid pelvic bone, tall and straight humerus, thickset joint surface, stubby metatarsal bones and phalanges, it boasted the maximum bearing capacity of body weight of terricolous backboned animals. Although it was giant in body conformation, it had a extremely disproportionate small head in the length of only 60cm. Based on the calculation carried out by scientists, it is estimated that it had to eat 300 kilograms of food to maintain the daily consumption of heavy body weight of 50 tons.

  Yangchuanosaurus shangyouensis      

Discovered in the upper reach of Yongchuan River in 1976, it was the natural enemy of Mamenchisaurus hochuanensis living in the same period. It was a carnivorous dinosaur with a body length of 8 meters and standing height of 4 meters. It had triangle-shaped solid skull with 6 couples of big holes on both sides. One couple of holes was eye holes, indicating it had excellent eye sight. The other holes were attached to the mighty head muscle groups used for worry and mastication. It had a relatively long tail tilted to keep physical balance in running, and short forelimbs with crooked and pointed claws. With long and sturdy hind limbs, it could run very fast with three toes touching down on the ground, in the manner of that of today's wading bird. It can be imagined that, it was very hard for sluggish Mamenchisaurus hochuanensis to escape from doom of being eaten up by Yangchuanosaurus shangyouensis, which had high running speed and fierce sharp teeth as well as razor-shaped claws.

Recently, a piece of dinosaurian scapula fossil was discovered in the suburb of Chongqing Municipality. Based on the fossil, specialists made a supposition that, this dinosaur, having a body length of more than 28 meters, was the largest one ever discovered in Asia up to now.