| Rio Piranhas Formation | |
| Type: | Geological formation |
| Period: | Hauterivian |
| Age: | Berriasian-Hauterivian |
| Prilithology: | Sandstone |
| Region: | Paraíba |
| Coordinates: | -6.7°N -38.5°W |
| Paleocoordinates: | -4.4°N -5.6°W |
| Unitof: | Rio do Peixe Group |
| Underlies: | undefined |
| Overlies: | Sousa Formation |
| Extent: | Triunfo Subbasin, Rio do Peixe Basin |
The Rio Piranhas Formation is a Berriasian to Hauterivian geologic formation in Paraíba, Brazil. Fossil ornithopod tracks have been reported from the formation.[1] Also fossils of Triunfosaurus leonardii have been found in the formation.[2]