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

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How sure are we?2 high20 medium4 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

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
high
high: 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.
high
high: 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
medium
medium: 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
medium
medium: Only PBDB gives this; nothing contradicts it.
Omnisaura calculation83.6–66 million years ago, from its dated fossil records
medium
medium: Omnisaura's calculation from 85 confirmed PBDB records.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Fossils found in: Canada
medium
medium: Only PBDB records it (49 records).
Russia
medium
medium: Only PBDB records it (2 records).
United States
medium
medium: Only PBDB records it (33 records).
China
low
low: Only one PBDB record.
mixed
mixed: 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
mixed
mixed: Levels differ between entries; each has its own.
Show all 13, each with its confidence
Dinosaur Park
medium
medium: Only PBDB records it (23 records).
Ferris
medium
medium: Only PBDB records it (5 records).
Hell Creek Formation
medium
medium: Only PBDB records it (7 records).
Horseshoe Canyon
medium
medium: Only PBDB records it (3 records).
Judith River Formation
medium
medium: Only PBDB records it (10 records).
Lance Formation
medium
medium: Only PBDB records it (3 records).
Oldman
medium
medium: Only PBDB records it (19 records).
Prince Creek
medium
medium: Only PBDB records it (5 records).
Two Medicine
medium
medium: Only PBDB records it (4 records).
Udurchukan
medium
medium: Only PBDB records it (2 records).
Wapiti
medium
medium: Only PBDB records it (2 records).
St. Mary River
low
low: Only one PBDB record.
Yuliangzi
low
low: Only one PBDB record.
Sources
Given by: Paleobiology Database. How it was chosen: Canonical names, automatic and editor-approved matches applied.
Family: Troodontidae
medium
medium: Only PBDB gives this; nothing contradicts it.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Parent group: Troodontinae
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: Troodon formosus
Sources
Given by: Paleobiology Database (the species its fossil records are identified as).
Older or other names: Polyodontosaurus (a junior synonym)
Sources
Given by: Paleobiology Database (names it treats as this genus).
Diet: carnivore, omnivore (inferred for its group)
medium
medium: Only PBDB gives this, and it infers it for the whole of Troodontidae, 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 (inferred for its group)
low
low: PBDB infers this way of life for the whole of Troodontidae; 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

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 the name in quotation marks).
Resting on one source: 5 facts come from a single source with nothing against them (rated medium): type species (PBDB); 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

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

Did it meet…?

Did Troodon 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.

Connections

Genera linked to Troodon 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 102

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

Triceratops Saurornitholestes Richardoestesia Paronychodon Edmontosaurus Tyrannosaurus Centrosaurus Dromaeosaurus Thescelosaurus Pachycephalosaurus Corythosaurus Stegoceras Chirostenotes Albertosaurus Chasmosaurus Lambeosaurusand 86 more

Same family: Troodontidae 16

Other genera in Troodontidae with a full profile.

Albertavenator Almas Anchiornis Archaeornithoides Borogovia Byronosaurus Daliansaurus Latenivenatrix Mei Pectinodon Saurornithoides Sinornithoides Sinovenator Stenonychosaurus Urbacodon Xenovenator

Named by Leidy 1

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

Hadrosaurus

Found in Canada 79

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

Saurornitholestes Richardoestesia Centrosaurus Paronychodon Dromaeosaurus Corythosaurus Chasmosaurus Albertosaurus Edmontosaurus Lambeosaurus Stegoceras Anodontosaurus Hypacrosaurus Gorgosaurus Triceratops Euoplocephalusand 63 more

Where its fossils were found

73 fossil sites, with present-day and ancient positions

Open the map at this time

Cite this page

Omnisaura (2026). Troodon. Future Sailors. https://www.omnisaura.com/genera/troodon. Data as of 5 October 2026.

What's changed

No changes since the change log started (11 Oct 2026).

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

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

The Childrens Museum of Indianapolis - Troodon teeth.jpg
Unknown author, CC BY-SA 3.0
Troodon formosus (feathers).JPG
Conty, CC BY 3.0
Troodon.jpg
Elekes Andor, CC BY-SA 4.0

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.