Ephemeroptera and the Great American Interchange

Abstract

The Panamerican Ephemeroptera fauna is evaluated with respect to the interchange of generic lineages and species between the Americas, and comparisons are drawn with classical studies of the American interchange based on other biota. Cladistic, distributional, and behavioral data are presented or reviewed that support the following hypotheses and conclusions: The Central American corridor has strongly favored northward dispersal, with 29 of 85 potential South American donor genera having infiltrated Central America, and 21 of those having further penetrated Nearctic North America. Only 10 of 63 potential North American donor genera have dispersed into Central America, and of those only Cercobrachys, Choroterpes, Epeorus, and Hexagenia have broached the Central American corridor. Only 8 species among the genera Campylocia, Cloeodes, Euthyplocia, Guajirolus, Hexagenia, Mayobaetis, and Tortopus co-occur in South and Central America. All belong to South American lineages, and 5 are large, relatively strong fl...