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Dinosaur genus

Troodon

Leidy 1856

Troodon is a dinosaur genus known from bones, found in rocks 83.6–66 million years old, in 4 countries, most often Canada and the United States.

Confidence labels
How sure are we?2 high19 medium3 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
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
Leidy 1856
highhigh: PBDB and Wikidata agree.
Sources

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

Described in
J. Leidy (1856). Notices of remains of extinct reptiles and fishes, discovered by Dr. F. V. Hayden in the bad lands of the Judith River, Nebraska Territory. Proceedings of the Academy of Natural Sciences of Philadelphia 8: 72–73.
highhigh: PBDB gives this publication for the name; its author and year match the naming authority (Leidy 1856), 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.

Type species
Troodon formosus
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

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

Lived
Campanian to Maastrichtian, 83.6–66 million years ago
mediummedium: Only PBDB gives this; nothing contradicts it.
Omnisaura calculation83.6–66 million years ago, from its dated fossil records
mediummedium: Omnisaura's calculation from 85 confirmed PBDB records.
Sources

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

Fossils found in
Canada
mediummedium: Only PBDB records it (49 records).
Russia
mediummedium: Only PBDB records it (2 records).
United States
mediummedium: Only PBDB records it (33 records).
China
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
13, including Dinosaur Park, Oldman, Judith River Formation and Hell Creek Formation
mixedmixed: Levels differ between entries; each has its own.
Show all 13, each with its confidence
Dinosaur Park
mediummedium: Only PBDB records it (23 records).
Ferris
mediummedium: Only PBDB records it (5 records).
Hell Creek Formation
mediummedium: Only PBDB records it (7 records).
Horseshoe Canyon
mediummedium: Only PBDB records it (3 records).
Judith River Formation
mediummedium: Only PBDB records it (10 records).
Lance Formation
mediummedium: Only PBDB records it (3 records).
Oldman
mediummedium: Only PBDB records it (19 records).
Prince Creek
mediummedium: Only PBDB records it (5 records).
Two Medicine
mediummedium: Only PBDB records it (4 records).
Udurchukan
mediummedium: Only PBDB records it (2 records).
Wapiti
mediummedium: Only PBDB records it (2 records).
St. Mary River
lowlow: Only one PBDB record.
Yuliangzi
lowlow: Only one PBDB record.
Sources

Given by: Paleobiology Database. How it was chosen: Canonical names, automatic and editor-approved matches applied.

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

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

Parent group
Troodontinae
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

  • 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: 18 fossil records left out: identified only tentatively (for example "cf." or "?").
  • Resting on one source: 4 facts come from a single source with nothing against them (rated medium): 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…?

?

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

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.

TriceratopsSaurornitholestesRichardoestesiaParonychodonEdmontosaurusTyrannosaurusCentrosaurusDromaeosaurusThescelosaurusPachycephalosaurusCorythosaurusStegocerasChirostenotesAlbertosaurusChasmosaurusLambeosaurusand 86 more

Same family

Other genera in Troodontidae with a full profile.

AlbertavenatorAlmasAnchiornisArchaeornithoidesBorogoviaByronosaurusDaliansaurusLatenivenatrixMeiPectinodonSaurornithoidesSinornithoidesSinovenatorStenonychosaurusUrbacodonXenovenator

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.