Letrero Formation
# Letrero Formation

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.

## Fossil content

The formation has provided fossils of:

* Anadasypus aequatorianus
* Caviomorpha indet.
* Litopterna indet.
* Toxodontia indet.
