Mamenchisauridae

Uragasaurus is a sauropod dinosaur, and the first mamenchisaurid known from Thailand. Mamenchisaurids exhibit the basic sauropod body plan, processing their herbivorous diet in their large gut. Uniquely, mamenchisaurid necks, like that of Uragasaurus, are proportionately long, even by sauropod standards.

Tongnanlong is a large mamenchisaurid sauropod dinosaur that lived in the Late Jurassic period of what is now China. Typical of mamenchisaurids, it had an extremely long neck, even by sauropod standards. Tongnanlong grew to approximately 25 m in length and weighed 20-30 t, making it one of the largest mamenchisaurids.