Mamenchisaurus fossil map
Where fossils of Mamenchisaurus have been found, shown on the Earth as it looked about 145 million years ago and on today’s map.
Dots are fossil collections recorded in the Paleobiology Database. The “then” view moves today’s fossil sites back to their positions 145 million years ago (the time slice nearest the median age of the fossils) using the Merdith et al. (2021) plate model; positions are approximate. Open on the timeline map →
| Group | Sauropods & prosauropods |
|---|---|
| Lived | 168.2–113.2 million years ago (Bathonian to Aptian) |
| Periods | Jurassic, Cretaceous |
| Family | Mamenchisauridae |
| Named by | Young 1954 |
| Fossil records | 24 occurrences at 18 locations (PBDB) |
| Found in | China, Mongolia, Thailand |
| Rock formations | Shaximiao, Ulan Malgait, Xiangtang, Phu Kradung, Shishugou, Dariv |
About Mamenchisaurus
Mamenchisaurus ( mə-MUN-chee-SOR-əs, or spelling pronunciation ) is an extinct genus of sauropod dinosaurs known for their remarkably long necks, which made up nearly half the total body length. Numerous species have been assigned to the genus; however, the validity of these assignments has been questioned. Fossils have been found in the Sichuan Basin and Yunnan Province in China. Several species from the Upper Shaximiao Formation, whose geologic age is uncertain, have been described. However, evidence suggests this formation to be no earlier than the Oxfordian stage of the Late Jurassic. M. sinocanadorum dates to the Oxfordian stage (161.2 to 158.7 mya), and M. anyuensis to the Aptian stage of the Early Cretaceous (around 114.4 mya). Most species were medium-large to large sauropods, measuring roughly 15 to 26 meters (49 to 85 ft) in length—possibly up to 35 meters (115 ft), based on two undescribed vertebrae.
Text in “About” is quoted from the Wikipedia article Mamenchisaurus (revision 1379824233), licensed under CC BY-SA 4.0; introduction excerpted verbatim, formatting removed. Ages, family, authority and fossil records: Paleobiology Database, accessed 22 October 2026. Ages are those of the rock layers the fossils were found in.
