Do mayflies (Ephemeroptera) support a biogeographic transition zone in South America?

摘要

Aim South America is considered a biologically hybrid continent. To the south, the Patagonian region harbours a unique biota strongly related to other southern continents. To the northern portion, tropical and subtropical areas from the Neotropical region show a more complex taxocoenosis related to the Nearctic and Afro-Oriental regions. The South American Transition Zone (STZ) has been proposed to belong simultaneously to both regions. This work aimed to test the validity of STZ in the light of the distributions of an ancient freshwater taxon.