 The refugial hypothesis is somewhat disputed as there is little field data to support or reject it.In any case it is simply one of several competing hypotheses to explain Amazonian biodiversity, each of which may or may not provide a good explanation for the geographical pattern found in any one group of taxa.In the present case, the refugia hypothesis is probably correct, as the Amazonian "Selenidera" have distributions "centered" on major river systems; they might be considered a superspecies.