Jurassic
Apatosaurus
Apatosaurus louisae
The catalogue presents Apatosaurus as a herbivore member of Diplodocidae that lived during the Jurassic, between 156.3–145.0 Ma. Its estimated range is 21.0–23.0 m in length and 16.4–22.4 t in mass, giving a practical sense of scale. Reference material comes from Carnegie Quarry, Morrison Formation, Utah, USA. Size and mass are approximations and may change with new fossils or methods.
Evidence-backed summary
For Apatosaurus, the PBDB records the taxonomic attribution as Marsh (1877).
The PBDB places it in Apatosaurinae, and the catalogue record assigns it to the family Diplodocidae.
- PBDB · taxon.parent
- Diplodocidae
The PBDB catalogues 5 occurrences, with material from the Morrison Formation (5). Provenance: United States.
The catalogue records the holotype as YPM 1860 and the type locality as “Morrison Formation, Colorado, USA”.
- YPM 1860
- Morrison Formation, Colorado, USA
The catalogue's reference measurements are 21.0–23.0 m in length and 16.4–22.4 t in mass — estimates, which vary with specimen and method.
- 21.0-23.0 m
- 16.4-22.4 tons
The record gathers 136 bibliographic references registered in the PBDB, listed below.
Where it lived
Fossil occurrences on today’s map and in the tectonic reconstruction.
Positions reconstructed by PBDB/GPlates, not observed; this is not an exact habitat map.
Artistic reconstruction · speculative details
Soft tissues and colours are speculative; the external form is an artistic interpretation.
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Physical Specifications
- Length
- 21.0–23.0 m
- Weight
- 16.4–22.4 t
- Period
- Jurassic
- Time range
- 156.3–145.0 Ma
Discovery Information
- First Discovery
- 1877
- Described by
- Othniel Charles Marsh
Taxonomic Classification
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Reptilia
- Order
- Saurischia
- Family
- Diplodocidae
- Genus
- Apatosaurus
- Species
- A. louisae
Data status
Taxonomic name matched to PBDB and checked on 2026-08-08.
Taxonomic linkage does not automatically validate size, mass, behaviour or appearance.
- Type specimen
- CM 3018
- Type locality
- Carnegie Quarry, Morrison Formation, Utah, USA