(Panephemeroptera Euephemeroptera Euplectoptera Anteritorna Bidentiseta Furcatergaliae  
Fimbriatotergaliae Fossoriae Ephemera/fg9 Hexagenia/fg1 Eatonica/g1 - Eatonigenia)

Nomen hierarchicum: Eatonigenia/g1 [g:1939]

In circumscription fits:

gen. Eatonigenia Ulmer 1939: 477

gen. Heterogenesia Dang 1967: 159

Eatonigenia/g1: Kluge 2004: 242

Nominal taxon included: Heterogenesia/g [g:1967]

References. Ulmer 1939: ; Dang 1967: ; McCafferty 1973: * *; Zhang 1988: ; Kluge 2004: * * *

Autapomorphies of Eatonigenia.

(1) On larval fore leg [burrowing see Fossoriae (1)] claw is vestigial, completely dipped into an incision on apex of tibia (McCafferty 1973: Fig.2324). Unique apomorphy.

(2) Penis lobes are fused all along their length and have a characteristic shape trapezoid, widened apically, with gonopores located on a pair of small ventral projections in proximal-median part (McCafferty 1973: Fig.912).

Character of Eatonigenia of unclear phylogenetic status. 

(3) Imaginal and subimaginal gonostylus with 1 distal segment only (instead of two initial ones). Non-unique apomorphy (see Index of characters [2.3.12]); among Ephemera/fg9 the same in Eatonica/g2 (possibly synapomorphy) and Pseudeatonica.

Plesiomorphy of Eatonigenia. Vestige of tergalius I [see Ephemera/fg9 (4)] is bilamellate (unlike Litobrancha).

Size. Fore wing length 1017 mm. 

Distribution. Oriental Region.

Nominal species in Eatonigenia/g1:

 chaperi Navás 1935 [Hexagenia] typus nominis Eatonigenia

 chinei Dang 1967 [Heterogenesia] typus nominis Heterogenesia

 indica Chopra 1924 [Hexagenia]

 philippina Navás 1933 [Hexagenia]

 seca McCafferty 1973 [Eatonigenia]

 trirama McCafferty 1973 [Eatonigenia]

 zhangi Sun & Luo & Zhou 2016 [Eatonigenia]