THE ZOOGEOGRAPHY AND CENTERS OF ORIGIN OF THE CRAYFISH SUBGENUS PROCERICAMBARUS (DECAPODA: CAMBARIDAE).

The Central Highlands region in the central United States is a taxonomically diverse region with a high incidence of stream endemism. Based on the distributions of the diverse ichthyofauna in the region, a pre-Pleistocene pattern of diversity due to vicariant events has been proposed to explain high levels of endemism and species richness. We tested this hypothesis using crayfish phylogenies and distributional patterns for species distributed in the Central Highlands region. We concluded that both pre-Pleistocene and Pleistocene hypotheses are compatible with the crayfish distributions and these distributions are likely due to a combination of both vicariant and dispersal events. Furthermore, we suggest a Pleistocene center of origin for the crayfish subgenus Procericambarus within the Ozark region and a pre-Pleistocene center of origin for the genus Orconectes within the Eastern Highlands region. © 1999 The Society for the Study of Evolution.