The Pebas Formation is a lithostratigraphic unit of Miocene age, found in western Amazonia. The formation extends over 1,000,000 square kilometres (390,000 sq mi), including parts of Brazil, Peru, Ecuador and Colombia.[1] It is interpreted as representing the deposits of a lake ("Lake Pebas") or series of lakes, formed within the foreland basin of the Andes mountain belt. It is known for its abundant fossil ostracods and molluscs and an unusually diverse group of crocodylians.[2]
Pebas Formation | |
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Stratigraphic range: Early Aquitanian-Tortonian (Colhuehuapian-Huayquerian) ~ | |
Underlies | Marañón Formation |
Overlies | Chambira Formation |
Area | 1,000,000 km2 (390,000 sq mi) |
Thickness | ~350–1,074 m (1,148–3,524 ft) |
Lithology | |
Primary | Siltstone, mudstone |
Other | Coal/lignite |
Location | |
Coordinates | 7°24′S 75°00′W / 7.4°S 75.0°W |
Approximate paleocoordinates | 8°24′S 70°36′W / 8.4°S 70.6°W |
Region | Amazon Basin |
Country | Brazil Colombia Ecuador Peru |
Type section | |
Named for | Pebas District |
Group | Fossils | Notes |
---|---|---|
Mammals | Dinomyidae indet., ?Octodontoidea indet. | |
Reptiles | Caiman wannlangstoni, Gnatusuchus pebasensis, Gryposuchus pachakamue, Purussaurus neivensis, Kuttanacaiman iquitosensis, Mourasuchus atopus, Paleosuchus sp., Podocnemis sp., Gavialoidea indet. | |
Fishes | cf. Hydrolycus sp., Leporinus sp., Potamotrygon sp., Pristis sp., Anostomidae indet. | |
Insects | Macroteleia yaguarum, Sycorax peruensis |
Formation | Honda | Honda | Aisol | Cura-Mallín | Pisco | Ipururo | Pebas | Capadare | Urumaco | Inés | Paraná | Map |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Basin | VSM | Honda | San Rafael | Caldera | Pisco | Ucayali | Amazon | Falcón | Venezuela | Paraná | ||
Country | Colombia | Bolivia | Argentina | Chile | Peru | Venezuela | Argentina | |||||
Boreostemma | ||||||||||||
Hapalops | ||||||||||||
Miocochilius | ||||||||||||
Theosodon | ||||||||||||
Xenastrapotherium | ||||||||||||
Mylodontidae | ||||||||||||
Sparassodonta | ||||||||||||
Primates | ||||||||||||
Rodents | ||||||||||||
Birds | ||||||||||||
Terror birds | ||||||||||||
Reptiles | ||||||||||||
megalodon | ||||||||||||
Flora | ||||||||||||
Insects | ||||||||||||
Environments | Fluvial | Fluvio-deltaic | Fluvio-lacustrine | Fluvio-deltaic | Fluvial | Laventan volcanoclastics Laventan fauna Laventan flora
| ||||||
Volcanic | Yes |
Formation | Cerro Azul | Ituzaingó | Paraná | Camacho | Raigón | Andalhuala | Chiquimil | Las Flores | Maimará | Palo | Pebas | Muyu | Rosa | Saldungaray | Salicas | Urumaco | Map |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Basin | Colorado | Paraná | Hualfín | Tontal | Andes | Salta | Amazon | Huasi | Altiplano | BA | Velasco | Falcón | |||||
Country | Argentina | Uruguay | Argentina | Brazil Peru |
Bolivia | Argentina | Venezuela | ||||||||||
Cardiatherium | |||||||||||||||||
Lagostomus | |||||||||||||||||
Macroeuphractus | |||||||||||||||||
Proeuphractus | |||||||||||||||||
Pronothrotherium | |||||||||||||||||
Pseudotypotherium | |||||||||||||||||
Thylacosmilus | |||||||||||||||||
Xotodon | |||||||||||||||||
Macraucheniidae | |||||||||||||||||
Primates | |||||||||||||||||
Rodents | |||||||||||||||||
Reptiles | |||||||||||||||||
Birds | |||||||||||||||||
Terror birds | |||||||||||||||||
Flora | |||||||||||||||||
Environments | Aeolian-fluvial | Fluvio-deltaic | Fluvial | Fluvio-lacustrine | Fluvial | Fluvio-lacustrine | Fluvio-deltaic | Huayquerian volcanoclastics Huayquerian fauna Huayquerian flora
| |||||||||
Volcanic | Yes |