Why does South America have fewer native artiodactyl groups than Africa?

South America has fewer native artiodactyl groups than Africa primarily because of its long history of geographic isolation. For most of its evolutionary history, the order Artiodactyla was absent from South America, as the continent remained disconnected from other landmasses following the breakup of Pangea.21

While Africa and Eurasia developed a diverse array of artiodactyls—including various bovids, giraffids, and hippopotamids—South America evolved a highly specialized, endemic fauna dominated by other groups, such as marsupial mammals.21

Artiodactyls only began to enter South America within the last few million years, following the formation of the land bridge across the isthmus of Panama. This event triggered a massive faunal exchange; however, many of the northern groups that migrated south, such as certain camelids, eventually went extinct in their original northern homelands, leaving only a few representatives like the guanaco and vicuña in South America. Consequently, the continent lacks the deep, long-term evolutionary history of artiodactyl diversification seen in the Old World.213