Mamenchisaurus is one of the sauropods, which are considered to be elephant-legged dinosaurs dominating the late Jurassic period. They are herbivores, though they were not as thick as their famous cousins, Apatosaurus and Argentinosaurus, they hold the record as the most impressive and longest neck over any other dinosaurs like them.

Key Facts

Mamenchisaurus pronunciationma-MEN-chih-SORE-us
What does Mamenchisaurus mean?Mamenchisaurus means “Mamenxi Lizard” which came from the Chinese word ma “horse, men “gate” and chi “steam” and a greek word sauros meaning “lizard. It was named after its first discovery in the locality of Mamenchi Ferry in the Yangtze River in China. 
Dinosaur typeSauropods
On the menuHerbivorous
Length15 to 35 meters (49-116 feet)
Height14 meters (46 feet)
Weight60,000 lbs
Life expectancyabout 100 years
Legs used to get aroundTheir long necks are so heavy making them move slowly with their four columnar legs which resemble the legs of an elephant.
Estimated top speedAbout 8 mph
When they livedThey lived during the late Jurassic period, about 150M to 160M years ago.
Where they have been found?The Mamenchisaurus fossils are widely found in China where the first fossils were found.

When & Where

The first recorded discovery of Mamenchisaurus was in Sichuan, China in 1952. Chinese Paleontologist, Chung Chien Young, described the first fossil (Mamenchisaurus neck) in 1954 after a long review, and the type is known as Mamenchisaurus constructus. It is then followed by more discoveries including those found in the Dashanpu Rock formation and in 1972 paleontologists Young & Zhao recovered a Mamenchisaurus hochuanensis. 

Size & Weight

The first discovery (mamenchisaurus neck) was not able to be measured since it was considered to be incomplete and too short. While the 1972 remains were estimated to be 72 feet long. 

Mobility & Diet

Mamenchisaurus are known to move slowly on their four legs. In case of food shortage, they used to travel in groups to search and migrate to survive hunger. It is known to be egg-hatching dinosaurs where they do not lay eggs in nests but in a linear pattern as they walk which then hatches on its own. They are herbivores which means they survived by eating leaves without the need to chew them with the help of “gastroliths” which are stomach stones that help in digesting through plants. Also, their teeth are blunt to help in stripping foliage. It is believed that their main food is conifers since it’s the most dominant type of plant in the sauropods era. Other food includes bennettitaleans, club mosses, cycads, Gingkos, ferns and seed ferns. 

Interesting Points

  • It was believed that they have an extra brain around their spinal cord, however, Paleontologists are still investigating, and presume that the said brain is just an enlargement in the spinal cord in the hip area. 
  • They are believed to have the lowest intelligence among all dinosaurs. 
  • Have hollow neck bones to help reduce the total weight of their neck 
  • Their heels have thick pads of fibrous tissues that provides cushion
  • In order to control its humongous legs and hips, they are equipped  with a second brain in their spinal cord located around the hip
  • Had 19 neck vertebrae