Dinosaur VaultEvery known dinosaur
Mamenchisaurus, Middle Jurassic to Early CretaceousShaximiao Formation, China · named 1954
See more pictures

Mamenchisaurus

mah-MEN-chee-SORE-us

Type species Mamenchisaurus constructus

Lived
168 to 137 million years ago, Middle Jurassic to Early Cretaceous
Diet
Herbivore
Group
Sauropods, Mamenchisauridae
Found in
China
Named by
Young 1954

Where its fossils were found

The evidence

Today

17 finds

155 million years ago

Map: C. R. Scotese, PALEOMAP

Also reported from Mongolia and Thailand.

Habitat

Rivers crossed the landscape preserved in the Shaximiao Formation, probably with woody vegetation along their banks. Regional neighbors included Tuojiangosaurus, Gigantspinosaurus and Yangchuanosaurus.

Field notes

About Mamenchisaurus

What it was like

Mamenchisaurus was a long-necked plant eater known for having one of the longest necks of any animal, making up nearly half its total body length. Its head was small compared to its body, and its neck was held up by long, overlapping vertebrae.

Like other sauropods, it walked on four thick, pillar-like legs and had a long, tapering tail. Exact size estimates vary widely between species and specimens, but Mamenchisaurus ranks among the largest animals ever to have lived.

Its world

Mamenchisaurus lived in what is now China from about 168 to 137 million years ago, spanning the Middle Jurassic to the Early Cretaceous, with possible finds also reported from Mongolia and Thailand. Its fossils come from formations including Shaximiao, Xiangtang, Penglaizhen, and Shishugou.

It shared its world with predators such as Yangchuanosaurus, Sinraptor, and Guanlong, the small plant eater Gongbusaurus, and the armored Gigantspinosaurus and Tuojiangosaurus.

How it was found

Young named Mamenchisaurus in 1954, based on fossils found in China. About 17 finds of the genus are now known, spread across several named species whose exact relationships are still debated. The type species is Mamenchisaurus constructus.

Field gallery

More views of Mamenchisaurus

Scenes reconstructed from the available fossil evidence.

Mamenchisaurus in its habitat, photo 1

1 of 7

Lived alongside

Found in the same rock formations

A rock formation can hold fossils laid down millions of years apart, so not every animal here met Mamenchisaurus.

The evidence

The science behind Mamenchisaurus

Which parts of the picture come from its own bones, and which come from its relatives.

From its own fossils

  • The incomplete skeleton of Mamenchisaurus constructus preserves a long series of neck bones and parts of the body and hind limbs.
  • A more complete skeleton of Mamenchisaurus youngi preserves the skull and neck, including long, overlapping neck ribs.
  • Scans of Mamenchisaurus sinocanadorum neck bones reveal extensive internal air spaces.

Borrowed from relatives

  • The missing head and forelimbs of Mamenchisaurus constructus are restored by comparison with Mamenchisaurus youngi and relatives such as Omeisaurus.
  • Xinjiangtitan helps estimate the missing portions of the exceptionally long neck in Mamenchisaurus sinocanadorum.

Still unknown

  • The precise head shape and forelimb anatomy of Mamenchisaurus constructus.
  • Its full adult size and the proportions of its young.
  • Which named species truly belong in Mamenchisaurus.

Often drawn wrong

  • Its long neck needs a supported curve rather than sharp bends like a swan's neck.
  • Its forefeet were upright weight-bearing structures, rather than flat hands with a row of spreading claws.

Discovery timeline

  1. 1954Named itYoung
  2. 2013PostureTaylor & Wedel
  3. 2013How it fedChristian et al.
  4. 2017PosturePAUL
  5. 2023Full descriptionMoore et al.

Key papers

The research behind what we know of Mamenchisaurus

Close relatives

Other members of Mamenchisauridae

Sources: Wikidata