(Panephemeroptera Euephemeroptera Euplectoptera Anteritorna Bidentiseta Branchitergaliae
Heptagennota Pentamerotarsata Radulapalpata Heptagenia/f5=g4 
Ecdyonurus/fg1 Atopopus/fg1 - Atopopus/fg2)

Nomen hierarchicum: Atopopus/fg2 [f:2004; g:1881] (sine Thamnodontus, Notacanthurus, Ecdyonuroides, Electrogena, Afronurus 

In circumscription fits:

gen. Atopopus Eaton 1881: 22

Atopopus/fg2: Kluge 2004: 182

References. Eaton 18831888: ; Wang & McCafferty 1995c: ; Kluge 2004: * * *.

Autapomorphies of Atopopus/fg2.

(1) Larva [flattened see Heptagennota (1)] has very wide head and relatively short legs; head shield is so sharply expanded laterally, that behind it head margin forms a pair of postero-lateral emarginations (Kluge 2004: Fig.59:A). In other Heptagennota such emarginations are either absent, or shallower.

(2) Dorsal lamella of tergalius I [curved dorsally see Ecdyonurus/fg1 (3) is vestigial, much smaller than ventral fibrillose lobe [see Ecdyonurus/fg1 (6)]. Non-unique apomorphy.

(3) Wings with characteristic brown pigmentation: on fore wing at distal part of costal area, at subcostal area and close to hind margin at cubital area; on hind wing close to margin at distal half. Non-unique character: the same in some Oriental species of Heptagenia/f6=g5.

Plesiomorphies of Atopopus/fg2. Unlike Afronurus/g1 and Electrogena, penis [see Pentamerotarsata (5)] has contiguous median titillators and distinct ventral and outer sclerites with laterodorsal spines (at least in tarsalis [A.]) (Kluge 2004: Fig.59:B-C).

Size. Fore wing length 1113 mm. 

Distribution. Oriental Region.

Nominal species in Atopopus/fg2:

 edmundsi Wang & McCafferty 1995 [Atopopus]

 tarsalis Eaton 1881 [Atopopus] typus nominis Atopopus /,(in T.Soldan's collection)

 tibialis Ulmer1920 [Atopopus]

See also:

Ecdyonurus/fg1 INCERTAE SEDIS

Radulapalpata INCERTAE SEDIS