Omnisaura
Demo

Dinosaur genus

Ammosaurus

Marsh 1891

Ammosaurus is a dinosaur genus known from bones, found in rocks 201.4–199.5 million years old.

Confidence labels
How sure are we?0 high6 medium0 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
201.4–199.5 Ma (published)
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
Marsh 1891
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

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

Described in
O. C. Marsh (1891). Notice of new vertebrate fossils. The American Journal of Science, series 3 42: 265–269. Read it
mediummedium: Only PBDB gives this; its author and year match the naming authority (Marsh 1891).
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
Ammosaurus major
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

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

Lived
Hettangian, 201.4–199.5 million years ago
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

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

Family
Anchisauridae
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

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

Parent group
Anchisauridae
mediummedium: 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.
  • Age (confirmed evidence): no source we use gives it yet.
  • Countries: no source we use gives it yet.
  • Formations: no source we use gives it yet.
  • Common names: no source we use gives it yet.
  • What it was named after: no source we use gives it yet.
  • Held back: 3 fossil records left out: identified only tentatively (for example "cf." or "?").
  • Resting on one source: 5 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).

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…?

?

Can't tell. One of them has no fossil age recorded.

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.

None in Omnisaura yet.

Same family

Other genera in Anchisauridae with a full profile.

ActiosaurusGyposaurus

Credits

Where this page comes from

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