Omnisaura
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Dinosaur genus

Edmontosaurus

Lambe 1917

Edmontosaurus is a dinosaur genus known from bones, found in rocks 89.8–66 million years old, in the United States and Canada.

Confidence labels
How sure are we?4 high9 medium6 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
89.8–66 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
Lambe 1917
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

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

Described in
L. M. Lambe (1917). A new genus and species of crestless hadrosaur from the Edmonton Formation of Alberta. The Ottawa Naturalist 31(7): 65–73.
mediummedium: Only PBDB gives this; its author and year match the naming authority (Lambe 1917).
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
Coniacian to Maastrichtian, 89.8–66 million years ago
highhigh: PBDB and NHM agree.
Omnisaura calculation89.8–66 million years ago, from its dated fossil records
mediummedium: Omnisaura's calculation from 68 confirmed PBDB records.
Sources

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

Fossils found in
Canada
highhigh: NHM and PBDB both record it.
United States
highhigh: 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
Laramie Formation
highhigh: NHM and PBDB both record it.
Frenchman
mediummedium: Only PBDB records it (2 records).
Hell Creek Formation
mediummedium: Only PBDB records it (29 records).
Horseshoe Canyon
mediummedium: Only PBDB records it (10 records).
Lance Formation
mediummedium: Only PBDB records it (18 records).
Edmonton Formation
disputedlow: Only NHM gives this name and it matches no PBDB formation; awaiting an editor.
Prince Creek
lowlow: Only one PBDB record.
Schrader Bluff
lowlow: Only one PBDB record.
St. Mary River
lowlow: Only one PBDB record.
Wapiti
lowlow: Only one PBDB record.
mixedmixed: Levels differ between entries; each has its own.
Sources

Given by: Paleobiology Database; Natural History Museum Data Portal. How it was chosen: Canonical names, automatic and editor-approved matches applied.

Family
Hadrosauridae
disputedlow: Sources disagree and an editor has not ruled yet.
Sources

Given by: Paleobiology Database; Natural History Museum Data Portal. How it was chosen: PBDB leads.

Parent group
Edmontosaurini
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

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

Order
Ornithischia
mediummedium: Only NHM gives this; nothing contradicts it.
Sources

Given by: Natural History Museum Data Portal. How it was chosen: Gap filled from NHM.

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.
  • Common names: no source we use gives it yet.
  • What it was named after: no source we use gives it yet.
  • Held back: 17 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): authority (PBDB); parent group (PBDB); order (NHM).

Size, diet and behaviour aren't covered yet. Omnisaura leaves them out rather than guess.

Where sources disagree

2 open

Family

  • HadrosauridaePBDB (shown above)
  • HadrosaruidaeNHM

The sources give different values. An editor hasn't ruled yet, so this is rated low until they do.

Formations

  • NonePBDB
  • Edmonton 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…?

?

Yes. Both are found, identified to species, in the same rocks of the same age: Frenchman, Hell Creek, Lance.

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.

TriceratopsTyrannosaurusThescelosaurusParonychodonRichardoestesiaPachycephalosaurusTroodonAlbertosaurusOrnithomimusAnodontosaurusPachyrhinosaurusChirostenotesSaurornitholestesAnkylosaurusDromaeosaurusSaurolophusand 37 more

Same family

Other genera in Hadrosauridae with a full profile.

AcheralichnusAcristavusAdelolophusAdynomosaurusAhshislesaurusAjnabiaAmurosaurusAnasazisaurusAngulomastacatorAquilarhinusAralosaurusArenysaurusAugustynolophusBarsboldiaBlasisaurusBonapartesaurusand 23 more

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.