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.
If two taxa are found in the same fossil quarry or at the same stratigraphic horizon, then their age-range zones overlap.
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.