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.RHM Locality 4 at Fossilworks.org
Fossil content
Mammals
Mammals of the Letrero Formation Genus Species Location Material Notes ImagesLitopternaIndeterminateRHM Locality 4A litoptern.CaviomorphaIndeterminateA caviomorph rodent.Nabondasypus Nabondasypus maddeniNabón basinSeveral osteoderms.An armadillo.AnadasypusCarlini et al., 2014A. aequatorianusRHM Locality 4A member of cingulata.ToxodontiaIndeterminateA toxodont.
See also List of fossiliferous stratigraphic units in Ecuador
References
Bibliography