title: Letrero Formation
text: # 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.
  