Mamenchisaurus hochuanensis — a long-necked sauropod
Mamenchisaurus was a giant sauropod with a very long neck — amongst the longest of any animal that has ever lived. Measuring up to 11 metres, the neck was almost half the overall length of the animal. Its long neck and its tail were held in position by a series of ligaments anchored at the hip — a bit like a suspension bridge. Mamenchisaurus would have walked with its stiff neck held almost horizontal. All the vertebrae of its neck, body and tail were hollow and light, while its leg bones were quite solid. This kept its centre of gravity low, which helped the animal maintain its balance.
Like all sauropods, Mamenchisaurus was a plant-eater. Its spoon-shaped teeth were not for chewing, but were used like a rake to strip leaves off plants. These were swallowed into its huge vat-like stomach. Its long neck allowed it to reach food otherwise inaccessible to an animal with such a huge body.
Mamenchisaurus, like all herbivores, would have had to eat continuously to get enough nutrition to sustain its massive body.