| Letrero Formation | |
|---|---|
| Stratigraphic range: Late Miocene (Mayoan-Montehermosan) ~ | |
| Type | Geological formation |
| Lithology | |
| Primary | Siltstone |
| Other | Sandstone |
| Location | |
| Coordinates | 3°18′S 79°06′W / 3.3°S 79.1°W / -3.3; -79.1 |
| Approximate paleocoordinates | 3°42′S 77°24′W / 3.7°S 77.4°W / -3.7; -77.4 |
| Region | Azuay Province |
| Country | Ecuador |
| Extent | Sierra Region |
Letrero Formation (Ecuador) | |
The Letrero Formation is a Late Miocene (Mayoan to Montehermosan in the SALMA classification) geologic formation in south-central Ecuador. The formation comprises lacustrine sediments with strong fluvial clastic input and contains siltstones and fine-grained sandstones.1
Fossil content
Mammals
| Mammals of the Letrero Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Location | Material | Notes | Images |
| Litopterna1 | Indeterminate | RHM Locality 4 | A litoptern. | ||
| Caviomorpha1 | Indeterminate | A caviomorph rodent. | |||
| Nabondasypus2 | Nabondasypus maddeni | Nabón basin | Several osteoderms. | An armadillo. |  |
| Anadasypus3 | A. aequatorianus | RHM Locality 4 | A member of cingulata. | ||
| Toxodontia1 | Indeterminate | A toxodont. | |||
References
References
- RHM Locality 4 at Fossilworks.org
- Barasoain, D.; Zurita, A. E.; Carrión, J. L.; Ñauñay Michilena, D. A.; Luna, C. A.; Miño-Boilini, A. R. (2026). "New endemic Dasypodidae (Xenarthra, Cingulata) from the Late Miocene of Ecuador and the importance of the tropics in the cladogenesis of armadillos". Journal of Systematic Palaeontology. 24 2648714. doi:10.1080/14772019.2026.2648714.
- Carlini et al., 2014
Bibliography
- Carlini, Alfredo A.; Castro, Mariela C.; Madden, Richard H.; Scillato Yané, Gustavo J. (2013), "A new species of Dasypodidae (Xenarthra: Cingulata) from the late Miocene of northwestern South America: implications in the Dasypodini phylogeny and diversity", Historical Biology: An International Journal of Paleobiology, 26 (6): 728–736, retrieved 2019-02-09