Jurassic
Marshosaurus
Marshosaurus bicentesimus
The catalogue presents Marshosaurus as a carnivore member of Piatnitzkysauridae that lived during the Jurassic, between 157.3–145.0 Ma. Its estimated range is 4.5–5.0 m in length and 200–300 kg in mass, giving a practical sense of scale. Reference material comes from Morrison Formation, Utah, USA. Size and mass are approximations and may change with new fossils or methods.
Evidence-backed summary
For Marshosaurus, the PBDB records the taxonomic attribution as Madsen (1976).
The PBDB places it in Marshosaurus, and the catalogue record assigns it to the family Piatnitzkysauridae.
- PBDB · taxon.parent
- Piatnitzkysauridae
In the PBDB record, the reported stratigraphic range runs from the Kimmeridgian to the Tithonian.
The PBDB catalogues 2 occurrences, with material from the Morrison Formation (2). Provenance: United States.
The catalogue records the holotype as UUVP 2826 and the type locality as “Morrison Formation, Utah, USA”.
- UUVP 2826
- Morrison Formation, Utah, USA
The catalogue's reference measurements are 4.5–5.0 m in length and 200–300 kg in mass — estimates, which vary with specimen and method.
- 4.5-5.0 m
- 200-300 kg
The record gathers 24 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
- 4.5–5.0 m
- Weight
- 200–300 kg
- Period
- Jurassic
- Time range
- 157.3–145.0 Ma
Discovery Information
- First Discovery
- 1976
- Described by
- James H. Madsen Jr.
Taxonomic Classification
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Reptilia
- Order
- Saurischia
- Family
- Piatnitzkysauridae
- Genus
- Marshosaurus
- Species
- M. bicentesimus
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
- UUVP 2826
- Type locality
- Morrison Formation, Utah, USA