THE GREAT AMERICAN INTERCHANGE – AN INVASION INDUCED CRISIS FOR SOUTH AMERICAN MAMMALS

During the Age of Mammals, South America was an isolated continent until the emergence of the Panamanian land bridge about 3.0 Ma; thereafter an intermingling of the long-separated North and South American faunas occurred. This, The Great American Interchange , is the most spectacular and best documented record of a reciprocal invasion of long separated continental faunas. In an attempt to understand short and long term consequences of faunal invasions of this magnitude taxonomic evolution (i.e. measurements of changes in number or frequency of different taxa) based on range distributions of families and genera of fossil mammals in South America is analyzed.