South American land mammal age

Background

Paleogeographic timeline

• 66 Ma – South America was connected to both North America and Antarctica. Soon after this point, it lost its connection to North America.
• 66–50 Ma – Tiupampan to Casamayoran - South America was connected to Antarctica which, in turn, was connected to Australia. The Antarctica–Australia connection was lost around the end of this interval or perhaps as much as 15 million years later.
• 50–34 Ma – Casamayoran to Tinguirirican - South America was connected to Antarctica, which was not yet covered by ice.
• 34 Ma – Tinguirirican - South America and Antarctica became detached and glaciations started to form in Antarctica.
• 34–9 Ma – Tinguirirican to Chasicoan - South America had no land connections to any other continent.
• 9–3 Ma – 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.
• 3 Ma to present – Uquian to Holocene - the land connection between South and North America is established and migration between the formerly separated continents occurs. The main migrational route is from north to south, rather than the opposite way. This led to much higher extinction levels of groups in South America than in North America.
• Pleistocene – 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 – 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

Fossil content