(Panephemeroptera Euephemeroptera Euplectoptera Anteritorna Bidentiseta Furcatergaliae  
Leptophlebia/fg1 Atalophleboadentata Atalophlebopectinata Atalophleboculata Atalophlebomaxillata Atalophlebolinguata 
... Hagenulus/fg1 Hermanellandria Hermanellonota - Hermanellognatha)

Nomen circumscribens: Hermanellognatha 

Nomen hierarchicum: Hermanella/f3=g2 [f:2008; g:1924] (sine Farrodes, Simothraulopsis, Homothraulus; incl. Traverella, Leentvaaria, Needhamella, Hylister)

In circumscription fits:

 Hermanella-complex: Traver 1960

 Hermanellognatha = Hermanella/fg2 = genus Hermanella: Kluge 2008: 394

References. Kluge 2008: * *.

Autapomorphies of Hermanellognatha.

(1) Mouth apparatus of "Dilatognathus-type" (Kluge 2012) (see Index of characters [1.1.12]), with unique structure of maxillary palp (see below); other mouth parts (labrum, mandibles, superlinguae, hypopharynx, maxillae and labium) are strongly widened and modified (Allen 1973: Fig.213; Dominguez & Flowers 1989: Fig.4282; 1982: Fig.1623).

Clypeus is sharply widened distally (see Index of characters [1.1.5]), its lateral margins have unique concave shape. In selected species (belonging to Traverella, Needhamella, Hydrosmilodon) clypeus bears an unpaired median protuberance or process, not found in other mayfly taxa (Kluge 2008: Fig.3839).

Labrum is strongly widened, wider than clypeus, but flat, not rolled ventrally (unlike some other taxa with widened labrum see Index of characters [1.1.13]). Shape of labrum is characteristic, with posterior margin straight and anterior margin convex, rounded; median emargination is narrowed and lost denticles [see Atalophleboculata (2)] (see Index of characters [1.1.16]). Regular transverse row of long setae [see Atalophlebopectinata (2)] is shifted to proximal part of labrum and interrupted medially (see Index of characters [1.1.14]) (Kluge 2008: Fig.3839).

Mandibles are flattened and widened correspondingly to clypeus and labrum, with outer margin angulate (see Index of characters [1.1.18]).

Inner-apical angle of maxilla is produced to a tusk-like process; this process varies in size, can be from huge to nearly absent. Dentiseta [see Atalophlebomaxillata (1)] and pectinate ventro-apical row of setae [see Leptophlebia/fg1 (1)] are lost (see Index of characters [1.1.31] and [1.1.37]).

Stipes of maxilla is shortened, so maxillary palp is attached close to articulation with cardo (see Index of characters [1.1.41]). 1st segment of maxillary palp is enormously shortened, its length does not exceed width, outer side with characteristic stout clavate setae; 2nd segment is the longest; 3rd (distal) segment bears numerous long filtering setae arranged in several regular transverse rows (Kluge 2008: Fig.37). In some other taxa setae of maxillary palp are also very long (see Index of characters [1.1.46]), but they do not form transverse rows.

These features of mouth apparatus are expressed both in mature and yang larvae. Significance of such mouth apparatus for feeding is not clear, as in guts of these larva is "found only fine detritus, as is common in the guts of many other mayflies" (Dominguez & Flowers 1989: 555).

(2) Larval pronotum is modified: free anterior margin (well expressed in other Hermanellandria) is not exprerssed, being smoothed out and all humeral setae [see Leptophlebia/fg1 (1.1)] are shifted backward to form a pair of compact bunches near midlength of lateral margins (Traver 1960:19-28: Fig.1).

(3) Styliger has a pair of processes dorsad of gonostyli bases.

Characters of Hermanellognatha of unclear phylogenetic status. 

(4) On fore wing fork of MP is asymmetrical (unlike Farrodes) (see Index of characters [2.2.46]).

Size. Fore wing length 613 mm.

Distribution. America, dominate in Neotropical Region.

The taxon Hermanellognatha (or Hermanella/fg2) is divided into:

1. Hermanella/fg3 (incl. Guayakia)

2. Traverella/g1 (incl. Zonda)

3. Needhamella/g1  (incl. Hydrosmilodon, Hydromastodon, Paramaka)

4. Leentvaria

5. Hylister

Hermenellognatha INCERTAE SEDIS