Letrero Formation

Letrero Formation Stratigraphic range: Late Miocene (Mayoan-Montehermosan) ~11.6–5.3 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Lithology
Primary	Siltstone
Other	Sandstone
Location
Coordinates	3°18′S 79°06′W / 3.3°S 79.1°W / -3.3; -79.1Coordinates: 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
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[]

The formation has provided fossils of:

• ^[2]
• Caviomorpha indet.
• Litopterna indet.
• Toxodontia indet.

See also[]

• List of fossiliferous stratigraphic units in Ecuador

References[]

Bibliography[]

• Carlini, Alfredo A.; Mariela C. Castro; Richard H. Madden, and Gustavo J. Scillato Yané. 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. 728–736. Accessed 2019-02-09.