CLADOENDESIS OF EPHEMEROPTERA
Heptagennota Pentamerotarsata Radulapalpata Heptagenia/f5=g4
Ecdyonurus/fg1 - Atopopus/fg1)
Nomen hierarchicum: Atopopus/fg1 [f:2004; g:1881] (incl. Thamnodontus, Notacanthurus, Ecdyonuroides, Electrogena, Afronurus)
In circumscription fits:
— Atopopus/fg1: Kluge 2004: 181
References. Kluge 2004: * * *
Autapomorphy of Atopopus/fg1.
(1) On maxilla [which proximal dentiseta divides into two branches – see Ecdyonurus/fg1 (2)] distal dentiseta divides into several branches divergent nearly from extreme base; thus the distal dentiseta looks as a bunch of stout setae (Kluge 2004: Fig.58:G-H). Unique apomorphy: in other Ecdyonurus/fg1 the distal dentiseta is integral, being either simple or bifurcate like the proximal one.
Among species examined, only a few exceptions are discovered: in Electrogena/g1 necatii [Ecdyonurus] all specimens have distal dentiseta integral, while in related species the distal dentiseta divides into branches (Belfiore, personal communication); among Ecdyonuroides/g1 sp.H4, some specimens have distal dentiseta integral, and some – divided into branches. Possibly, these exceptions are results of secondary reversions.
Character of Atopopus/fg1 of unclear phylogenetic status.
(2) Primary swimming setae [see Pentamerotarsata (6)] are lost; larval caudalii have only whorls of setae on ends of segments [see Heptagenia/f5=g4 (2)]. Non-unique character (see Index of characters [1.3.66]); among Ecdyonurus/fg1 the same in Leucrocuta/fg1.
Size. Fore wing length 7–15 mm.
Distribution. Old World: Palaearctic, Oriental and Afrotropical Regions.
|The taxon Atopopus/fg1 is divided into:|
1. plesiomorphon Thamnodontus
Some poorly known taxa have uncertaein systematic position