Omnisaura

Dinosaur genus

Iguanodon

Mantell 1825

Iguanodon is a dinosaur genus known from bones, found in rocks 154.8–100.5 million years old, in 8 countries, most often the United Kingdom and Spain.

Also calledes Iguanodonteja イグアノドンzh 禽龙
mediummedium: Only Wikidata gives this; nothing contradicts it.
Confidence labels
How sure are we?10 high14 medium21 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
154.8–100.5 Ma
Triassic
Jurassic
Cretaceous
252 million years ago20114366

Solid: the ages of its dated fossils, 154.8–100.5 million years ago (Omnisaura's calculation). Pale: the published range, 154.8–66 million years ago, which also counts records Omnisaura leaves out.

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
Mantell 1825
highhigh: PBDB and Wikidata agree.
Sources

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

Described in
G. A. Mantell (1825). Notice on the Iguanodon, a newly discovered fossil reptile, from the sandstone of Tilgate Forest, in Sussex. Philosophical Transactions of the Royal Society of London 115: 179–186.
highhigh: PBDB gives this publication for the name; its author and year match the naming authority (Mantell 1825), 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
Kimmeridgian to Maastrichtian, 154.8–66 million years ago
disputedlow: Sources disagree and an editor has not ruled yet.
Omnisaura calculation154.8–100.5 million years ago, from its dated fossil records
mediummedium: Omnisaura's calculation from 107 confirmed PBDB records.
Sources

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

Fossils found in
Germany
highhigh: NHM and PBDB both record it.
United Kingdom
highhigh: NHM and PBDB both record it.
France
mediummedium: Only PBDB records it (4 records).
Portugal
mediummedium: Only PBDB records it (4 records).
Spain
mediummedium: Only PBDB records it (35 records).
Belgium
lowlow: Only one PBDB record.
China
lowlow: Only one PBDB record.
Tunisia
disputedlow: NHM records it here but PBDB has no record in this country; awaiting an editor.
mixedmixed: Levels differ between entries; each has its own.
Sources

Given by: Paleobiology Database; Natural History Museum Data Portal. How it was chosen: Union of all sources (ISO 3166).

Rock formations
29, including Weald Clay Formation, Arcillas de Morella, Wessex Formation and Tunbridge Wells Sand Formation
mixedmixed: Levels differ between entries; each has its own.
Show all 29, each with its confidence
Ashdown Formation
highhigh: NHM and PBDB both record it.
Tunbridge Wells Sand Formation
highhigh: NHM and PBDB both record it.
Vectis Formation
highhigh: NHM and PBDB both record it.
Wadhurst Clay Formation
highhigh: NHM and PBDB both record it.
Weald Clay Formation
highhigh: NHM and PBDB both record it.
Wessex Formation
highhigh: NHM and PBDB both record it.
Arcillas de Morella
mediummedium: Only PBDB records it (12 records).
Camarillas
mediummedium: Only PBDB records it (8 records).
Capas Rojas
mediummedium: Only PBDB records it (2 records).
El Collado
mediummedium: Only PBDB records it (2 records).
Huérteles
mediummedium: Only PBDB records it (3 records).
Papo Seco
mediummedium: Only PBDB records it (2 records).
Woburn Sand
mediummedium: Only PBDB records it (2 records).
Argile Ostréenne
lowlow: Only one PBDB record.
Bückeberg
lowlow: Only one PBDB record.
Calcaires à Spatangues
lowlow: Only one PBDB record.
Camadas de Almargem
lowlow: Only one PBDB record.
Gault Formation
disputedlow: Only NHM gives this name and it matches no PBDB formation; awaiting an editor.
Grès et Sables Piquetés
lowlow: Only one PBDB record.
Haoling
lowlow: Only one PBDB record.
Kimmeridge Clay Formation
disputedlow: Only NHM gives this name and it matches no PBDB formation; awaiting an editor.
Ladeiras
lowlow: Only one PBDB record.
Oxford Clay Formation
disputedlow: Only NHM gives this name and it matches no PBDB formation; awaiting an editor.
Pinilla de los Moros
lowlow: Only one PBDB record.
Sainte-Barbe Clays
lowlow: Only one PBDB record.
Sandgate
lowlow: Only one PBDB record.
Tilgate Grit
disputedlow: Only NHM gives this name and it matches no PBDB formation; awaiting an editor.
Upper Greensand Formation
disputedlow: Only NHM gives this name and it matches no PBDB formation; awaiting an editor.
West Melbury Marly Chalk Formation
disputedlow: Only NHM gives this name and it matches no PBDB formation; awaiting an editor.
Sources

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

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

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

Species named in its records
Iguanodon anglicum, Iguanodon bernissartensis, Iguanodon galvensis, Iguanodon major, Iguanodon mantelli, Iguanodon seelyi
Sources

Given by: Paleobiology Database (the species its fossil records are identified as).

Older or other names
Heterosaurus (a junior synonym); Iguanosaurus (a junior synonym); Struthopus (a junior synonym); Therosaurus (a junior synonym)
Sources

Given by: Paleobiology Database (names it treats as this genus).

Diet
herbivore (inferred for its group)
mediummedium: Only PBDB gives this, and it infers it for the whole of Ornithopoda, 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)
lowlow: PBDB infers this way of life for the whole of Ornithischia; 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.
  • Family: no source we use gives it yet.
  • What it was named after: no source we use gives it yet.
  • Held back: 26 fossil records left out: identified only tentatively (for example "cf.", "?" or the name in quotation marks).
  • Held back: 1 fossil record left out: identified as a related genus rather than this one.
  • Held back: 1 fossil record left out: identified only to a broader group, not to this genus.
  • Resting on one source: 3 facts come from a single source with nothing against them (rated medium): parent group (PBDB); common names (Wikidata); 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

8 open

Age

  • 154.8–66 MaPBDB
  • 184.2–93.9 MaNHM specimens

The ages of the records reach well beyond the published range. An editor hasn't ruled yet, so this is rated low until they do.

Formations

  • records nothing herePBDB
  • Gault FormationNHM

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
  • Kimmeridge Clay FormationNHM

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
  • Oxford Clay FormationNHM

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
  • Tilgate GritNHM

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
  • Upper Greensand FormationNHM

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
  • West Melbury Marly Chalk FormationNHM

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

Countries

  • BE, CN, DE, ES, FR, GB, PTPBDB
  • TunisiaNHM

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

Did it meet…?

?

No. Iguanodon had gone at least 16.9 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.

Connections

Genera linked to Iguanodon by where and when their fossils were found, by classification and by who named them. Select a name to open its page.

IguanodonSame rocks, same timeSame parent groupSame naming authorAlso found in United KingdomMantellisaurusPolacanthusValdosaurusHylaeosaurusand 25 moreBayannurosaurusCamptosaurusPelorosaurusand 1 moreHypselospinusMegalosaurusCetiosaurusOrnithopsisand 18 more

Same rocks, same time 29

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

MantellisaurusPolacanthusValdosaurusHylaeosaurusHypselospinusIguanodontipusMegalosaurusBaryonyxCetiosaurusBariliumBrontopodusCaririchniumHypsilophodonKalohipusMetatetrapousOrnithopsisand 13 more

Same parent group: Ankylopollexia 2

Other genera in Ankylopollexia with a full profile.

BayannurosaurusCamptosaurus

Named by Mantell 2

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

HylaeosaurusPelorosaurus

Found in United Kingdom 22

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

PolacanthusHylaeosaurusHypselospinusMegalosaurusValdosaurusMantellisaurusCetiosaurusOrnithopsisBariliumEchinodonHypsilophodonBaryonyxIguanodontipusNuthetesAristosuchusBrighstoneusand 6 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.