Cretaceous
Achelousaurus
Achelousaurus horneri
The catalogue presents Achelousaurus as a herbivore member of Ceratopsidae that lived during the Cretaceous, between 74 Ma. Its estimated range is 6.0 m in length and 2.7 t in mass, giving a practical sense of scale. Reference material comes from Montana, USA. Size and mass are approximations and may change with new fossils or methods.
Evidence-backed summary
For Achelousaurus, the PBDB records the taxonomic attribution as Sampson (1994).
The PBDB places it in Pachyrhinosaurini, and the catalogue record assigns it to the family Ceratopsidae.
- PBDB · taxon.parent
- Ceratopsidae
In the PBDB record, the reported stratigraphic range is the Campanian.
The PBDB catalogues 2 occurrences, with material from the Two Medicine Formation (2). Provenance: United States.
The catalogue records the holotype as MOR 485 and the type locality as “Montana, USA”.
- MOR 485
- Montana, USA
The catalogue's reference measurements are 6.0 m in length and 2.7 t in mass — estimates, which vary with specimen and method.
- 6.0 m
- 2.7 tons
The record gathers 17 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 3D reconstruction
There is no approved species-specific 3D model yet. Generic anatomy will not be presented as if it were evidence.
Physical Specifications
- Length
- 6.0 m
- Weight
- 2.7 t
- Period
- Cretaceous
- Time range
- 74 Ma
Discovery Information
- First Discovery
- 1994
- Described by
- Scott Sampson
Taxonomic Classification
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Reptilia
- Order
- Ornithischia
- Family
- Ceratopsidae
- Genus
- Achelousaurus
- Species
- A. horneri
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
- MOR 485
- Type locality
- Montana, USA