Dinosaur genus
Orodromeus
Orodromeus is a dinosaur genus known from bones, found in rocks 83.6–66 million years old, in the United States.
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 11 October 2026- Named by
- Horner and Weishampel 1988
high
high: PBDB and Wikidata agree.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Described in
- J. R. Horner, D. B. Weishampel (1988). A comparative embryological study of two ornithischian dinosaurs. Nature 332: 256–257. Read it
high
high: PBDB gives this publication for the name; its author and year match the naming authority (Horner and Weishampel 1988), 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 this; nothing contradicts it.Omnisaura calculation83.6–66 million years ago, from its dated fossil recordsmedium
medium: Omnisaura's calculation from 7 confirmed PBDB records.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Fossils found in
- United States
medium
medium: Only PBDB records it (7 records).Sources
Given by: Paleobiology Database. How it was chosen: Union of all sources (ISO 3166).
- Rock formations
- Two MedicineHell Creek Formation
medium
medium: Only PBDB records it (5 records).Judith River Formationlow
low: Only one PBDB record.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: Canonical names, automatic and editor-approved matches applied.
- Family
- Thescelosauridae
disputed
low: Sources disagree and an editor has not ruled yet.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Parent group
- Orodrominae
medium
medium: Only PBDB gives this; nothing contradicts it.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Order
- Ornithischia
medium
medium: Only NHM gives this; nothing contradicts it.Sources
Given by: Natural History Museum Data Portal. How it was chosen: Gap filled from NHM.
- Species named in its records
- Orodromeus makelai
Sources
Given by: Paleobiology Database (the species its fossil records are identified as).
- Diet
- herbivore (inferred for its group)
medium
medium: Only PBDB gives this, and it infers it for the whole of Ornithischia, 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 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).
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: 2 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); order (NHM); 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
1 openFamily
- ThescelosauridaePBDB (shown above)
- HipsilophodontidaeNHM
The sources give different values. 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: Hell Creek.
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 Orodromeus 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 58
Genera found in the same rock units, from rocks of overlapping age, the most shared fossil sites first.
Same family: Thescelosauridae 11
Other genera in Thescelosauridae with a full profile.
Named by Horner and Weishampel 4
Genera whose naming authority includes the same surname. The authority has no initials, so different people who share a surname can appear together.
Found in United States 105
Other genera found in United States, from rocks of overlapping age, the most fossil sites there first.
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.