Cretaceous
Thescelosaurus
Thescelosaurus neglectus
The catalogue presents Thescelosaurus as a herbivore member of Thescelosauridae that lived during the Cretaceous, between 93.9–72.2 Ma. Its estimated range is 3.5–4.0 m in length and 200–300 kg in mass, giving a practical sense of scale. Reference material comes from Lance Formation, Wyoming, USA. Size and mass are approximations and may change with new fossils or methods.
Evidence-backed summary
For Thescelosaurus, the PBDB records the taxonomic attribution as Gilmore (1913).
The PBDB places it in Thescelosaurinae, and the catalogue record assigns it to the family Thescelosauridae.
- PBDB · taxon.parent
- Thescelosauridae
In the PBDB record, the reported stratigraphic range runs from the Turonian to the Maastrichtian.
The PBDB catalogues 28 occurrences, with material from the Hell Creek Formation (15), from the Oldman Formation (4) and from the Dinosaur Park Formation (4). Provenance: United States and Canada.
The catalogue records the holotype as USNM 7757 and the type locality as “Lance Formation, Wyoming, USA”.
- USNM 7757
- Lance Formation, Wyoming, USA
The catalogue's reference measurements are 3.5–4.0 m in length and 200–300 kg in mass — estimates, which vary with specimen and method.
- 3.5-4.0 m
- 200-300 kg
The record gathers 91 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
- 3.5–4.0 m
- Weight
- 200–300 kg
- Period
- Cretaceous
- Time range
- 93.9–72.2 Ma
Discovery Information
- First Discovery
- 1913
- Described by
- Charles Sternberg
Taxonomic Classification
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Reptilia
- Order
- Ornithischia
- Family
- Thescelosauridae
- Genus
- Thescelosaurus
- Species
- T. neglectus
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
- USNM 7757
- Type locality
- Lance Formation, Wyoming, USA