Abstract
Recent discovery and description of fossil Baetiscidae has dramatically changed the biogeographical and evolutionary perspective of the family. Since the mid-eighteenth century until recently, the family has been known only from the Nearctic realm and all extant species of the family still remain geographically limited to this region. Here, we present the first parsimony algorithm generated cladistic analysis of the phylogeny of Baetisca based on external morphological characters of both larvae and adults. The results are compared with the previously published phylogeny of the genus and differences between the two studies are discussed. The southeastern United States is the centre of biodiversity of the genus where 11 of the 12 currently known nominal species have been reported. Biogeographical and evolutionary implications of the current geographic range of extant Baetisca and fossil species are discussed.
Acknowledgements
We thank Jan Peters, Florida A&M University, for her encouragement and critical review of the manuscript. Our gratitude to Steven Burian, Southern Connecticut State University; David Funk, Academy of Natural Sciences, Pennsylvania; Peter Grant, Southwestern Oklahoma State University; Jerry Louton, National Museum of Natural History, Washington DC; and Jeff Webb, Purdue University, Indiana, for the loan of Baetisca specimens. Helen Barber-James, Albany Museum, Grahamstown, South Africa, made possible the investigation of Prosopistoma variegatum. Our appreciation to Katherine Milla, Florida A&M University, for her assistance in generating the GIS map. Milan Pallmann, SMNS, is thanked for taking the photograph of P. bechlyi. This research was partially supported by a research grant (Flax2002-0002) from CSREES\USDA to Florida A&M University.