Omnisaura

Dinosaur genus

Ceratosaurus

Marsh 1884

Ceratosaurus is a dinosaur genus known from bones, found in rocks 157.9–143.1 million years old, in the United States, Portugal and Tanzania.

Also calleden Ceratosaurus ("horned lizard")
mediummedium: Only Wikidata gives this; nothing contradicts it.
Confidence labels
How sure are we?2 high11 medium1 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
157.9–143.1 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
Marsh 1884
highhigh: PBDB and Wikidata agree.
Sources

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

Described in
O. C. Marsh (1884). Principal characters of American Jurassic dinosaurs. Part VIII. The order Theropoda. The American Journal of Science, series 3 27: 329–340. Read it
highhigh: PBDB gives this publication for the name; its author and year match the naming authority (Marsh 1884), on which PBDB and Wikidata agree.
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.

Lived
157.9–143.1 million years ago
mediummedium: Only PBDB gives this; nothing contradicts it.
Omnisaura calculation157.9–143.1 million years ago, from its dated fossil records
mediummedium: Omnisaura's calculation from 27 confirmed PBDB records.
Sources

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

Fossils found in
Portugal
mediummedium: Only PBDB records it (4 records).
Tanzania
mediummedium: Only PBDB records it (3 records).
United States
mediummedium: Only PBDB records it (18 records).
Sources

Given by: Paleobiology Database. How it was chosen: Union of all sources (ISO 3166).

Rock formations
Lourinhã
mediummedium: Only PBDB records it (3 records).
Morrison Formation
mediummedium: Only PBDB records it (18 records).
Tacuarembó
mediummedium: Only PBDB records it (2 records).
Tendaguru Formation
mediummedium: Only PBDB records it (3 records).
Praia da Amoreira-Porto Novo
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.

Parent group
Ceratosauria
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), Natural History Museum Data Portal (CC0 1.0), Wikidata (CC0 1.0)Confidence levels and gaps are Omnisaura's own assessment.

Gaps are answers

What isn't known yet

  • Type species: no source we use gives it yet.
  • Order: no source we use gives it yet.
  • Family: no source we use gives it yet.
  • What it was named after: no source we use gives it yet.
  • Held back: 2 fossil records left out: identified only tentatively (for example "cf." or "?").
  • Resting on one source: 3 facts come from a single source with nothing against them (rated medium): parent group (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…?

?

No. Ceratosaurus had gone at least 59.5 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.

Same parent group

Other genera in Ceratosauria with a full profile.

Credits

Where this page comes from

  • Paleobiology DatabaseCC BY 4.0 · fossil records, ages, classification
  • Natural History Museum Data PortalCC0 1.0 · catalogued specimens
  • 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.