Dinosaur genus
Apatosaurus
Apatosaurus is a dinosaur genus known from bones, found in rocks 157.9–143.1 million years old, in the United States.
medium
medium: Only Wikidata gives this; nothing contradicts it.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- Named by
- Marsh 1877
high
high: PBDB and Wikidata agree.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Described in
- O. C. Marsh (1877). Notice of new dinosaurian reptiles from the Jurassic formation. American Journal of Science and Arts 14: 514–516. Read it
high
high: PBDB gives this publication for the name; its author and year match the naming authority (Marsh 1877), 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
- 157.9–143.1 million years ago
high
high: PBDB and NHM agree.Omnisaura calculation157.9–143.1 million years ago, from its dated fossil recordsmedium
medium: Omnisaura's calculation from 60 confirmed PBDB records.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Fossils found in
- United States
high
high: 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
- Morrison Formation
high
high: NHM and PBDB both record it.Sources
Given by: Paleobiology Database; Natural History Museum Data Portal. How it was chosen: Canonical names, automatic and editor-approved matches applied.
- Family
- Diplodocidae
medium
medium: Only PBDB gives this; nothing contradicts it.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Parent group
- Apatosaurinae
medium
medium: Only PBDB gives this; nothing contradicts it.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Order
- Saurischia
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.
- 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.
- What it was named after: no source we use gives it yet.
- Held back: 7 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): parent group (PBDB); family (PBDB); order (NHM); common names (Wikidata).
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…?
No. Apatosaurus had gone at least 59.5 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.
Lived alongside
Genera found in the same rock formations, from rocks of the same age.
Same family
Other genera in Diplodocidae with a full profile.
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.