Omnisaura

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
mediummedium: Only Wikidata gives this; nothing contradicts it.
Confidence labels
How sure are we?0 high12 medium9 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 5 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
mediummedium: 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.
mediummedium: 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
mediummedium: 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
mediummedium: Only PBDB gives this; nothing contradicts it.
Omnisaura calculation168.2–113.2 million years ago, from its dated fossil records
mediummedium: Omnisaura's calculation from 17 confirmed PBDB records.
Sources

Given by: Paleobiology Database. How it was chosen: PBDB leads.

Fossils found in
China
mediummedium: Only PBDB records it (15 records).
Mongolia
lowlow: Only one PBDB record.
Thailand
lowlow: Only one PBDB record.
mixedmixed: 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
mediummedium: Only PBDB records it (8 records).
Xiangtang
mediummedium: Only PBDB records it (2 records).
Dariv
lowlow: Only one PBDB record.
Penglaizhen
lowlow: Only one PBDB record.
Phu Kradung
lowlow: Only one PBDB record.
Shishugou
lowlow: Only one PBDB record.
Suining
lowlow: Only one PBDB record.
Upper Shaximiao
lowlow: Only one PBDB record.
mixedmixed: 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
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

Given by: Paleobiology Database. How it was chosen: PBDB leads.

Parent group
Mamenchisauridae
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

Given by: Paleobiology Database. How it was chosen: PBDB leads.

Species named in its records
Mamenchisaurus anyuensis, Mamenchisaurus constructus, Mamenchisaurus hochuanensis, Mamenchisaurus jingyanensis, Mamenchisaurus sanjiangensis, Mamenchisaurus sinocanadorum, Mamenchisaurus youngi
Sources

Given by: Paleobiology Database (the species its fossil records are identified as).

Diet
herbivore (inferred for its group)
mediummedium: Only PBDB gives this, and it infers it for the whole of Sauropoda, the group this genus belongs to, not from this genus's own fossils.
Sources

Given by: Paleobiology Database. How it was chosen: PBDB, inferred from a group the genus belongs to.

Way of life
ground dwelling, gregarious (inferred for its group)
lowlow: PBDB infers this way of life for the whole of Sauropoda; behaviour is rarely known for one genus.
Sources

Given by: Paleobiology Database. How it was chosen: PBDB, inferred from a group the genus belongs to.

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 the name in quotation marks).
  • Resting on one source: 7 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); diet (PBDB).

Size and appearance aren't covered yet, and diet and way of life only as PBDB infers them for the wider group. Omnisaura leaves the rest out rather than guess.

Where sources disagree

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

Did it 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.

Connections

Genera linked to Mamenchisaurus by where and when their fossils were found, by classification and by who named them. Select a name to open its page.

Same rocks, same time 15

Genera found in the same rock units, from rocks of overlapping age, the most shared fossil sites first.

Same family: Mamenchisauridae 9

Other genera in Mamenchisauridae with a full profile.

Named by Young 9

Genera whose naming authority includes the same surname. The authority has no initials, so different people who share a surname can appear together.

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.