Mamenchisaurus

Phylogeny: Dinosauria > Saurischia > Sauropodomorpha > Plateosauria > Massopoda > Sauropodiformes > Sauropoda > Gravisauria > Eusauropoda > Mamenchisauridae

Overview: In the 1950’s, a team of road workers in the Sichuan Province of China stumbled upon the fossils of a large dinosaur. The fossils were described in 1954 by paleontologist Yang Zhongjian, known to his western peers as C. C. Young, as a new genus. Yang, who was by far the most prolific Chinese paleontologist at that time, gave it the name Mamenchisaurus – the “Mamenxi lizard”. This name was meant to refer to Mamingxi, the area where it was found, which Yang would mistake for the similarly named “Mamenxi”. Most of the remains recovered included vertebrae from the neck and tail, as well as some limb material. In the years to follow, scientists would describe many other Mamenchisaurus specimens from all over China. Currently, around eight or so species are assigned to the genus. Yang’s specimen was found in the famous Shaximiao Formation, but other supposed species came from many other geological formations, representing an oddly wide span of time for a dinosaur genus. For this reason, it’s likely not all of these species belong to Mamenchisaurus, but we can’t be certain until Yang’s holotype specimen is re-described in more rigorous detail.

Some of the referred species of Mamenchisaurus were quite large, being over twenty or possibly even thirty meters in length, making it one of the largest dinosaurs known from China. Others were more modest in size, at maybe fifteen meters long. In any case, the necks of these animals tended to be quite long in proportion to the rest of the body. Among the largest Mamenchisaurus species, the neck could be between twelve and fifteen meters long by themselves, meaning it had one of the longest necks of any known dinosaur. Mamenchisaurus was, undoubtedly, a high-browser, able to feed from branches out of reach from the other sauropods it lived with. Even if it turns out that most of the species referred to Mamenchisaurus don’t belong to the genus, there’s a good chance they were still close relatives. Mamenchisaurus is the namesake of the family Mamenchisauridae, classified as a group of basal eusauropods. For the most part, these sauropods lived in Asia, though at least one genus has been described from Africa. They too possessed proportionately long necks, even by sauropod standards, as well as a wide range of body sizes as adults.