The South American land mammal ages (SALMA) establish a geologic timescale for prehistoric South American fauna beginning 64.5 Ma during the Paleocene and continuing through to the Late Pleistocene (0.011 Ma). These periods are referred to as ages, stages, or intervals and were established using geographic place names where fossil materials where obtained.
The basic unit of measurement is the first/last boundary statement. This shows that the first appearance event of one taxon is known to predate the last appearance event of another. If two taxa are found in the same fossil quarry or at the same stratigraphic horizon, then their age-range zones overlap.
Background
South America was an island continent for much of the Cenozoic, or the "Age of Mammals". As a result, its mammals evolved in their own unique directions, as Australia and Madagascar still have today.
Paleogeographic timeline
A simplified paleogeographic timeline of South America:
- 66 Ma â South America was connected to both North America and Antarctica. Soon after this point, it lost its connection to North America.
- 66âÂÂ50 Ma â Tiupampan to Casamayoran - South America was connected to Antarctica which, in turn, was connected to Australia. The AntarcticaâÂÂAustralia connection was lost around the end of this interval or perhaps as much as 15 million years later.
- 50âÂÂ34 Ma â Casamayoran to Tinguirirican - South America was connected to Antarctica, which was not yet covered by ice.
- 34 Ma â Tinguirirican - South America and Antarctica became detached and glaciations started to form in Antarctica.
- 34âÂÂ9 Ma â Tinguirirican to Chasicoan - South America had no land connections to any other continent.
- 9âÂÂ3 Ma â Huayquerian to Chapadmalalan - islands formed between South and North America. A complete Isthmus of Panama most likely formed near the end of this interval, leading to the Great American Biotic Interchange (GABI).
- 3 Ma to present â Uquian to Holocene - the land connection between South and North America is established and migration between the formerly separated continents occurs. Significantly higher rates of extinction due to climatic changes occur in South America compared to North America, resulting in an asymmetrical exchange of species between the continents. North American originating taxa diversify significantly in South America during this period. It was previously believed this asymmetry was due to the main migrational route being from north to south, rather than the opposite way.
- Pleistocene â the glacials and interglacials of the Pleistocene caused drastic eustatic sea level changes, widening and narrowing the land bridge at the 'bottleneck' of Panama. As a side-effect, the vegetation changed during this period of strong climatic changes.
- Late Pleistocene â the earliest humans arrived in South America and settled in various parts of the continent. Evidence for cohabitation with the latest Pleistocene megafauna has been found at multiple locations, such as Monte Verde in coastal Chile and Tibitó on the Altiplano Cundiboyacense in Colombia.
Definitions
Cenozoic fossiliferous stratigraphic units in South America
The following formations have provided vertebrate, insect or plant fossils, formations with other invertebrates are excluded:
Fossil content
See also
Notes and references
Notes
References
Bibliography
SALMA
Paleogene
Pebas Wetlands
Argentina
Paleogene
Pleistocene
Austral Basin
Santa MarÃÂa-HualfÃÂn Basin
Santa Fe Province
Aconquija Formation
Agua de la Piedra Formation
Aisol Formation
Andalhuala Formation
Andesitas Huancache Formation
Arroyo Chasicó Formation
Belgrano Formation
Bororó Formation
Brochero Formation
Casamayor Formation
Cerro Azul Formation
Cerro Bandera Formation
Chapadmalal Formation
Chichinales Formation
Chiquimil Formation
Collón Curá Formation
Deseado Formation
Divisadero Largo Formation
La Ensenada Formation
Las Flores Formation, Sierra del Tontal
Las Flores Formation, Golfo San Jorge Basin
FortÃÂn Tres Pozos Formation
Gaiman Formation
Geste Formation
Gran Bajo del Gualicho Formation
Hernandarias Formation
HuayquerÃÂas Formation
Huitrera Formation
India Muerta Formation
La Invernada Formation
Ituzaingó Formation
Koluel Kaike Formation
Laguna Brava Formation
Laguna del Hunco Formation
Lefipán Formation
Leticia Formation
Loma de Las Tapias Formation
Luján Formation
Lumbrera Formation
Maimará Formation
MaÃÂz Gordo Formation
Mariño Formation
Mealla Formation
Miramar & San Andrés Formations
Monte Hermoso Formation
Monte León Formation
El Morterito Formation
Palo Pintado Formation
Paraná Formation
Peñas Coloradas Formation
Pinturas Formation
Piquete Formation
Playa de Los Lobos Allo Formation
Puerta del Diablo Formation
Puerto Madryn Formation
Quebrada de Los Colorados Formation
RÃÂo Chico Group
RÃÂo Foyel Formation
RÃÂo Loro Formation
RÃÂo Mayo Formation
RÃÂo Negro Formation
RÃÂo Quinto Formation
Saladillo Formation
Salamanca Formation
Saldungaray Formation
Salicas Formation
Santa Cruz Formation
Sarmiento Formation & Colhué HuapàMember
Toro Negro Formation
UquÃÂa Formation
Vaca Mahuida Formation
Ventana Formation
Vorohué Formation
YupoÃÂ Formation
Bolivia
Casira Formation
Cerdas beds
Honda Group
Lacayani fauna
ÃÂuapua Formation
Quehua Formation
Salla Formation
Santa LucÃÂa Formation
Tarija Formation
Umala Formation
Yecua & Petaca Formations
Brazil
Entre-Corrégos Formation
Fonseca Formation
Graxaim Formation
Guabirotuba Formation
Içá Formation
ItaboraÃÂ Formation
Maria Farinha Formation
Pirabas Formation
Rio Madeira Formation
Santa Vitória Formation
Solimões Formation
Touro Passo Formation
Tremembé Formation
Chile
Abanico Formation
BahÃÂa Inglesa Formation
Caleta Herradura Formation
ChÃÂu-ChÃÂu Formation
Chucal Formation
Coquimbo Formation
Cura-MallÃÂn Group
Horcón Formation
Huaylas Formation
Loreto Formation
Navidad Formation
La Portada Formation
RÃÂo Baguales Formation
RÃÂo FrÃÂas Formation
Colombia
Altiplano Cundiboyacense
Cesar-RancherÃÂa Basin
Cocinetas Basin
Barzalosa Formation
Gualanday Group
Honda Group
Los Hoyos beds
Mugrosa Formation
Rotinet Formation
Sincelejo Formation
Ecuador
Biblián Formation
Dos Bocas Formation
Letrero Formation
Onzole Formation
Seca Formation
Paraguay
Chaco Formation
Peru
Peruvian Amazon
Sechura Basin
Chambira Formation
Chilcatay Formation
Chota Formation
Iñapari Formation
Madre de Dios Formation
Mogollón Formation
Moquegua Formation
Muñani Formation
Paracas Formation
Pisco Formation
Pozo Formation
Soncco Formation
Yahuarango Formation
Yumaque Formation
Uruguay
Pleistocene
Camacho Formation
Dolores Formation
Fray Bentos Formation
Raigón Formation
San José Formation
Sopas Formation
Venezuela
Chaguaramas Formation
Parángula Formation
Falcón Basin
Cantaure & Paraguaná Formations
Capadare Formation
Castillo Formation
Mesa Formation
RÃÂo Yuca Formation
San Gregorio Formation
Santa Inés Formation
Urumaco, Socorro & Codore Formations
Further reading