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

Abstract

Recent discovery and description of fossil Baetiscidae has dramatically changed the biogeographical and evolutionary perspective of the family. Since the mideighteenth 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.

Revised systematics, phylogeny, and paleontology of the mayfly family Baetiscidae (Insecta: Ephemeroptera)

“…Later, Edmunds and Traver (1954) also supported this classification under the new rank Prosopistomatoidea. While some authors had proposed different phylogenies for the two families (Landa andSoldán 1985, McCafferty 1991), a sistergroup relationship of Baetiscidae and Prosopistomatidae has by now been accepted by most other authors (Kluge 1995, McCafferty 1997, 2001, Kluge 2004, Staniczek 2007, Pescador et al 2009 and was finally also corroborated by genomic data (Ogden et al 2009). Other names coined for this monophyletic group were Baetiscoidea (Peters and Hubbard 1989), Posteritorna (Kluge 1995), andCarapacea (Mc-Cafferty 2004).…”

“…In order to perform an integrated phylogenetic analysis of fossil and extant Baetiscidae, the character matrix using morphological data of extant Baetiscidae used by Pescador et al (2009) was modified and 14 additional characters were introduced (see Table S2 and Table S3). The combined data analysis included both nymphal and adult characters, with 36 characters in total.…”

“…We analysed 14 ingroup taxa. Outgroup taxon was Prosopistoma variegatum as already used by Pescador et al (2009). Parsimony methods were conducted using TNT 1.5 (Goloboff and Catalano 2016) (data matrix in Table S3).…”

“…Synapomorphies of Baetisca species are the approximated penis lobes (22:1), the presence of a middorsal transverse elevation on tergum VI (32:1), and in the female the presence of an apical cleft on sternum IX (33:1). The positions of the different Baetisca species were recovered unchanged as in Pescador et al (2009).…”

“…The Baetiscidae, or "armored mayflies" (Insecta: Ephemeroptera) currently comprise ten valid extant species (Pescador and Berner 1981). They are a well-defined monophyletic group (Pescador et al 2009): their hind wings are of almost circular shape, and adult stages have a bispinate prosternal projection; both characters are generally regarded as autapomorphies of the group (Pescador et al 2009). Their nymphs have developed a characteristically shaped, massive notal shield, which dorsally covers most abdominal segments to form a breathing chamber (Notestine 1993).…”