Einiosaurus — artistic reconstruction

Cretaceous

Einiosaurus

Einiosaurus procurvicornis

The catalogue presents Einiosaurus as a herbivore member of Ceratopsidae that lived during the Cretaceous, between 74.0–72.0 Ma. Its estimated range is 4.5–6.0 m in length and 1.2–2.5 t in mass, giving a practical sense of scale. Reference material comes from Two Medicine Formation, Montana, USA. Size and mass are approximations and may change with new fossils or methods.

Herbivore74.0–72.0 MaCeratopsidae

Evidence-backed summary

For Einiosaurus, 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.

In the PBDB record, the reported stratigraphic range is the Campanian.

The PBDB catalogues 3 occurrences, with material from the Two Medicine Formation (3). Provenance: United States.

The catalogue records the holotype as MOR 456 and the type locality as “Two Medicine Formation, Montana, USA”.

  • MOR 456
  • Two Medicine Formation, Montana, USA

The catalogue's reference measurements are 4.5–6.0 m in length and 1.2–2.5 t in mass — estimates, which vary with specimen and method.

  • 4.5-6.0 m
  • 1.2-2.5 tons

The record gathers 16 bibliographic references registered in the PBDB, listed below.

Records compiled on 2026-08-08

Where it lived

Fossil occurrences on today’s map and in the tectonic reconstruction.

Present-day map3 PBDB
Two MedicineTwo MedicineTwo Medicine
PBDB occurrences
Map at the time · ~80 Ma3 PBDB
Two MedicineTwo MedicineTwo Medicine
PBDB occurrences
Present mean latitude49.0° N
Reconstructed mean latitude59.4° N

Positions reconstructed by PBDB/GPlates, not observed; this is not an exact habitat map.

Paleobiology Database · GPlates · CC BY 4.0

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
4.5–6.0 m
Weight
1.2–2.5 t
Period
Cretaceous
Time range
74.0–72.0 Ma

Discovery Information

First Discovery
1995
Described by
Scott Sampson

Taxonomic Classification

Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Ornithischia
Family
Ceratopsidae
Genus
Einiosaurus
Species
E. procurvicornis

Paleobiology Database · txn:53952

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 456
Type locality
Two Medicine Formation, Montana, USA