Mamenchisaurus Click to enlarge image
Illustration of Mamenchisaurus by James Reece. Image: James Reece
© Australian Museum

Fast Facts

  • Classification


Mamenchisaurus youngi was a gigantic herbivore that lived around 150 million years ago and had one of the longest necks of all known dinosaurs.


Mamenchisaurus youngi had:

  • a nine-metre-long neck to help it reach leaves high up in trees;
  • hollows in its neck bones to reduce the weight of its neck;
  • a large and powerful heart to pump blood to the head;
  • strong and thick blood vessels to cope with its high blood pressure;
  • thick pads of fibrous tissues on its heels to help cushion its great weight;
  • a 'second brain' in the spinal cord in the hip to help control its hind legs and tail.

Fossils description

Mamenchisaurus is named after Mamen Brook, in Sichuan where it was first found.

Evolutionary relationships

Mamenchisaurus youngi was a sauropod belonging to the Chinese family Euhelopodidae, a group of massive dinosaurs that lived from the Late Jurassic to the Early Cretaceous.