Evolution of Baetiscidae (Ephemeroptera): current state of knowledge of the family

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.