FACT SHEET: mamenchisaurus NAME: MAMENCHISAURUS (mah-MEN-kee-SAW-rus), “Mamen Brook Lizard” SIZE: 70 - 80 feet long (the size of an airplane), weighed 12 tons TYPE OF DIET: Herbivore (conifers, horsetails, club mosses, ferns gingko leaves) WHEN: Late Jurassic period (156 - 145 million years ago) WHERE: China Mamenchisaurus lived about 156 to 145 million years ago. It had the longest neck of any animal that we know of. Mamenchisaurus was about 70 to 80 feet long and weighed about 12 tons. Its neck was about 46 feet long, around half of the entire length of its body. Its neck vertebrae were hollow – and in some places as thin as an eggshell. This made its neck very light, so Mamenchisaurus could move its long neck around easily. Mamenchisaurus held its neck straight out from its body, parallel to the ground. This made it possible for it to eat plants growing low to the ground as well as leaves on high trees. Mamenchisaurus lived on conifers, horsetails, club mosses and ferns. These plants had soft leaves, which were easier to digest. It also ate leaves from gingko trees. It moved about slowly on four legs. Its hind legs were longer than the front legs. It swallowed leaves whole without chewing them. Along with the leaves, this dinosaur also swallowed small stones called gastroliths. Mamenchisaurus may have traveled in herds or groups. Once the dinosaurs ate everything in their area, they all moved together to a new place. These dinosaurs might have lived to be 100 years old. Mamenchisaurus fossils have mainly been found in China. The name means “Mamen Brook lizard”, which tells us where it was found. It lived in wet areas, probably at the banks of rivers and brooks. Dinosaur Days TM © 2010 Distant Train, inc. (www.distanttrain.com) all rights reserved.