Raigón Formation

The Raigón Formation is a geologic formation in Uruguay dated between the Pliocene and Middle Pleistocene.^[1]

Raigón Formation
Stratigraphic range: Pliocene–Middle Pleistocene PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Underlies	Libertad Formation
Overlies	Fray Bentos Formation
Lithology
Primary	siltstone
Location
Country	Uruguay
Type section
Named for	Raigón, Uruguay
Raigón Formation, Uruguay

Overview

In 1966, Uruguayan geologists Héctor Goso and Jorge Bossi defined the Raigón Formation, which they subdivided into the San José Member (the same as Francis and Mones' San José Formation) below and the San Bautista Member above.^[2] In 1988, Álvaro Mones identified Lower Pleistocene levels in the San José Member.^[3] In 2002, American geologist H. McDonald and Uruguayan paleontologist Daniel Perea suggested the formation may represent a wide timespan from the Montehermosan all the way to the Ensenadan.^[4]

A notable finding was J. monesi, recovered in situ from a boulder originating in the San José Member. The boulder is made up of siltstone, claystone, and medium-grained and medium-to-conglomeratic psammite (a type of sandstone) intercalated with siltstone.^[5]

Fossil content

The following fossils have been reported from the formation:

• Charruatoxodon^[6]
• Desmodus draculae^[7]
• Trigodon sp.^[6]
• Catonyx tarijensis^[6]
• Pronothrotherium figueirasi^[6]
• Glyptodon^[6]
• Plaxhaplous^[6]
• Giganhinga^[6]
• Josephoartigasia monesi^[5]
• Pronothrotherium^[8]
• Uruguayurus^[1]
• Cardiatherium talicei^[1]
• Uruguayodon^[9]
• Platygonus sp.^[10]
• Phorusrhacinae (possibly Devincenzia)^[11][12]
• Homotherini - previously assigned to cf. Xenosmilus sp.,^[13] but its generic attribution is uncertain.^[14][15]

See also

• List of fossiliferous stratigraphic units in Uruguay