Dinosaur genus

Ornithomimus

Marsh 1890

Ornithomimus is a dinosaur genus known from bones, found in rocks 83.6–66 million years old, in the United States and Canada.

Confidence labels

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How sure are we?4 high10 medium11 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 10 October 2026

83.6–66 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 1890
high
high: PBDB and Wikidata agree.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Described in: O. C. Marsh (1890). Description of new dinosaurian reptiles. The American Journal of Science, series 3 39: 81–86. Read it
high
high: PBDB gives this publication for the name; its author and year match the naming authority (Marsh 1890), 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: Campanian to Maastrichtian, 83.6–66 million years ago
medium
medium: Only PBDB gives a range this precise; NHM's records give only a broader interval, which contains it.
Omnisaura calculation83.6–66 million years ago, from its dated fossil records
medium
medium: Omnisaura's calculation from 27 confirmed PBDB records.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Fossils found in: Canada
high
high: NHM and PBDB both record it.
United States
high
high: NHM and PBDB both record it.
Sources
Given by: Paleobiology Database; Natural History Museum Data Portal. How it was chosen: Union of all sources (ISO 3166).
Rock formations: 15, including Lance Formation, Horseshoe Canyon, Dinosaur Park and Denver
mixed
mixed: Levels differ between entries; each has its own.
Show all 15, each with its confidence
Denver
medium
medium: Only PBDB records it (2 records).
Dinosaur Park
medium
medium: Only PBDB records it (3 records).
Hell Creek Formation
medium
medium: Only PBDB records it (2 records).
Horseshoe Canyon
medium
medium: Only PBDB records it (5 records).
Lance Formation
medium
medium: Only PBDB records it (6 records).
Aguja
low
low: Only one PBDB record.
Belly River Series
disputed
low: Only NHM gives this name and it matches no PBDB formation; awaiting an editor.
Frenchman
low
low: Only one PBDB record.
Fruitland
low
low: Only one PBDB record.
Judith River Formation
low
low: Only one PBDB record.
Kaiparowits
low
low: Only one PBDB record.
Laramie Formation
disputed
low: Only NHM gives this name and it matches no PBDB formation; awaiting an editor.
Scollard
low
low: Only one PBDB record.
Tar Heel
low
low: Only one PBDB record.
Two Medicine
low
low: Only one PBDB record.
Sources
Given by: Paleobiology Database; Natural History Museum Data Portal. How it was chosen: Canonical names, automatic and editor-approved matches applied.
Family: Ornithomimidae
medium
medium: Only PBDB gives this; nothing contradicts it.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Parent group: Ornithomimidae
medium
medium: Only PBDB gives this; nothing contradicts it.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Species named in its records: Ornithomimus edmontonicus, Ornithomimus minutus, Ornithomimus sedens, Ornithomimus tenuis, Ornithomimus velox
Sources
Given by: Paleobiology Database (the species its fossil records are identified as).
Diet: herbivore, omnivore (inferred for its group)
medium
medium: Only PBDB gives this, and it infers it for the whole of Ornithomimosauria, 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)
low
low: PBDB infers this way of life for the whole of Ornithomimosauria; 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), 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.
Common names: no source we use gives it yet.
What it was named after: no source we use gives it yet.
Held back: 8 fossil records left out: identified only tentatively (for example "cf.", "?" or the name in quotation marks).
Resting on one source: 4 facts come from a single source with nothing against them (rated medium): parent group (PBDB); family (PBDB); age (headline) (PBDB); 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

2 open

Formations

records nothing herePBDB
Belly River SeriesNHM

One source names a formation the other does not. An editor hasn't ruled yet, so this is rated low until they do.

Formations

records nothing herePBDB
Laramie FormationNHM

One source names a formation the other does not. An editor hasn't ruled yet, so this is rated low until they do.

Did it meet…?

Did Ornithomimus meet ?

Yes. Both are found, identified to species, in the same rocks of the same age: Denver, Dinosaur Park, Lance.

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 Ornithomimus 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 98

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

Triceratops Richardoestesia Saurornitholestes Edmontosaurus Paronychodon Tyrannosaurus Troodon Thescelosaurus Centrosaurus Pachycephalosaurus Stegoceras Corythosaurus Dromaeosaurus Chirostenotes Albertosaurus Chasmosaurusand 82 more

Same family: Ornithomimidae 6

Other genera in Ornithomimidae with a full profile.

Aepyornithomimus Anserimimus Archaeornithomimus Dromiceiomimus Gallimimus Struthiomimus

Named by Marsh 18

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

Allosaurus Ammosaurus Anchisaurus Apatosaurus Barosaurus Brontosaurus Camptosaurus Ceratosaurus Claosaurus Coelurus Diplodocus Dryosaurus Dryptosaurus Nanosaurus Nodosaurus Stegosaurusand 2 more

Found in United States 105

Other genera found in United States, from rocks of overlapping age, the most fossil sites there first.

Triceratops Tyrannosaurus Edmontosaurus Richardoestesia Paronychodon Thescelosaurus Saurornitholestes Troodon Pachycephalosaurus Alamosaurus Stegoceras Dromaeosaurus Kritosaurus Agujaceratops Chirostenotes Parasaurolophusand 89 more

Where its fossils were found

25 fossil sites, with present-day and ancient positions

Open the map at this time

Cite this page

Omnisaura (2026). Ornithomimus. Future Sailors. https://www.omnisaura.com/genera/ornithomimus. Data as of 10 October 2026.

What's changed

19 Oct 2026
Age (PBDB): confidence high → medium.

Every change to Omnisaura

Use this data

Download this genus as JSON With every source and licence attached. Also recorded in: Paleobiology Database · Wikipedia (English) · GBIF · Wikidata Spotted a problem? Tell us

Pictures

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

-Ornithomimus- sp. by Tom Parker (flipped).png
Tom Parker, CC BY-SA 4.0
Ornithomimus edmontonicus.jpg
Sebastian Bergmann from Siegburg, Germany, CC BY-SA 2.0
OrnithomimusROM.JPG
Eduard Solà, CC BY-SA 3.0
NHM-UK_P_DF118_03_24_0407
The Trustees of the Natural History Museum, London, CC BY 4.0

The rest are listed in the JSON download.

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.