Dinosaur genus

Mamenchisaurus

Young 1954

Mamenchisaurus is a dinosaur genus known from bones, found in rocks 168.2–113.2 million years old, in China, Mongolia and Thailand.

Also calledja マメンチサウルスzh 馬門溪龍

medium

medium: Only Wikidata gives this; nothing contradicts it.

Confidence labels

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How sure are we?0 high11 medium8 lowHow we rate confidence

Confidence labels are switched off. Facts with low confidence, or where sources disagree, still carry a small dot: tap it for the reason.

At a glance

Data as of 12 October 2026

168.2–113.2 Ma

Triassic

Jurassic

Cretaceous

252 million years ago20114366

The last non-bird dinosaurs died out 66 million years ago. That's as far from us as the end of this bar.

Named by: Young 1954
medium
medium: Only PBDB gives this; nothing contradicts it.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Described in: C.-C. Young (1954). On a new sauropod from Yiping, Szechuan, China. Acta Paleontologica Sinica 2(4): 355–369.
medium
medium: Only PBDB gives this; its author and year match the naming authority (Young 1954).
Sources
Given by: Paleobiology Database. The publication the Paleobiology Database gives as the authority for this genus name, usually the one that first named and described it.
Type species: Mamenchisaurus constructus
medium
medium: Only PBDB gives this; nothing contradicts it.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Lived: Bathonian to Aptian, 168.2–113.2 million years ago
medium
medium: Only PBDB gives this; nothing contradicts it.
Omnisaura calculation168.2–113.2 million years ago, from its dated fossil records
medium
medium: Omnisaura's calculation from 17 confirmed PBDB records.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Fossils found in: China
medium
medium: Only PBDB records it (15 records).
Mongolia
low
low: Only one PBDB record.
Thailand
low
low: Only one PBDB record.
mixed
mixed: Levels differ between entries; each has its own.
Sources
Given by: Paleobiology Database. How it was chosen: Union of all sources (ISO 3166).
Rock formations: Shaximiao
medium
medium: Only PBDB records it (8 records).
Xiangtang
medium
medium: Only PBDB records it (2 records).
Dariv
low
low: Only one PBDB record.
Penglaizhen
low
low: Only one PBDB record.
Phu Kradung
low
low: Only one PBDB record.
Shishugou
low
low: Only one PBDB record.
Suining
low
low: Only one PBDB record.
Upper Shaximiao
low
low: Only one PBDB record.
mixed
mixed: Levels differ between entries; each has its own.
Sources
Given by: Paleobiology Database. How it was chosen: Canonical names, automatic and editor-approved matches applied.
Family: Mamenchisauridae
medium
medium: Only PBDB gives this; nothing contradicts it.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Parent group: Mamenchisauridae
medium
medium: Only PBDB gives this; nothing contradicts it.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Known from: Bones
Sources
Given by: Paleobiology Database (what the name was based on).

Sources: Paleobiology Database (CC BY 4.0), Wikidata (CC0 1.0)Confidence levels and gaps are Omnisaura's own assessment.

Gaps are answers

What isn't known yet

Order: no source we use gives it yet.
What it was named after: no source we use gives it yet.
Held back: 7 fossil records left out: identified only tentatively (for example "cf." or "?").
Resting on one source: 6 facts come from a single source with nothing against them (rated medium): authority (PBDB); type species (PBDB); parent group (PBDB); family (PBDB); age (headline) (PBDB); common names (Wikidata).

Size, diet and behaviour aren't covered yet. Omnisaura leaves them out rather than guess.

Where sources disagree

None open. Where our sources overlap, they agree on everything shown here.

Did it meet…?

Did Mamenchisaurus meet ?

No. Mamenchisaurus had gone at least 29.6 million years before Tyrannosaurus appears in the fossil record.

Going by the ages and rock formations of their dated fossils, as on the map. Compare their fossil sites on the map.

Lived alongside

Genera found in the same rock formations, from rocks of the same age.

Omeisaurus Shunosaurus Chungkingosaurus Tienshanosaurus Datousaurus Gongbusaurus Limusaurus Sinraptor Yangchuanosaurus Abrosaurus Agilisaurus Bashanosaurus Chuandongocoelurus Daanosaurus Jialingpus

Same family

Other genera in Mamenchisauridae with a full profile.

Abrosaurus Analong Anhuilong Bellusaurus Chuanjiesaurus Daanosaurus Omeisaurus Tienshanosaurus Wamweracaudia

Where its fossils were found

15 fossil sites, with present-day and ancient positions

Open the map at this time

Cite this page

Omnisaura (2026). Mamenchisaurus. Future Sailors. https://www.omnisaura.com/genera/mamenchisaurus. Data as of 12 October 2026.

What's changed

No changes since the change log started (11 Oct 2026).

Every change to Omnisaura

Use this data

Download this genus as JSON With every source and licence attached. Spotted a problem? Tell us

Pictures

2 openly licensed pictures of Mamenchisaurus on Wikimedia Commons and museum sites, each with its own author and licence.

Mamenchisaurus hochuanensis sauropod dinosaur (Shangshaximiao Formation, Upper Jurassic; Gushushan, NW of Hechuan, southwestern Chongqing Municipality, south-central China) 2 (15407361402).jpg
James St. John, CC BY 2.0
Mamenchisaurus youngi steveoc 86.jpg
Steveoc 86, CC BY-SA 2.5

Credits

Where this page comes from

Paleobiology DatabaseCC BY 4.0 · fossil records, ages, classification
WikidataCC0 1.0 · names and identifiers
OmnisauraOmnisaura editorial · confidence levels and gaps
PaleoMAP PaleoCoastlines (Kocsis and Scotese 2021)CC BY 4.0 · ancient coastlines on the small map
Natural EarthPublic domain · today's coastlines

Pictures linked from this page are credited beside each one, with their own licences; the full list is in the JSON download.