(Panephemeroptera Euephemeroptera Euplectoptera Anteritorna pm.Tridentiseta  
Tetramerotarsata - Siphlaenigma)

Nomen hierarchicum: Siphlaenigma/fg(1) [fg:1962]

In circumscription fits:

— gen. Siphlaenigma Penniket 1962: 389

— subfam. Siphlaenigmatinae: McCafferty & Edmunds 1979: 6

— fam. Siphlaenigmatidae Penniket 1962: 389

— Siphlaenigma/fg(1): Kluge 2004: 100

References. Penniket 1962: ; – Edmunds & Allen & Peters 1963: ; – Tshernova 1970: ; – Edmunds & Jensen & Berner 1976: ; – Kluge 1997c: (plesiomorphies wrongly named "Apomorphies of Siphlaenigma"); – Staniczek 1997: ; – Lugo-Ortiz & McCafferty 1998: ; – Kluge 2004: .

Characters of Siphlaenigma of unclear phylogenetic status.

(1) In female imago and subimago (unlike male) structure of fore tarsus is the same as of middle and hind tarsus [see Tetramerotarsata (1)]: tarsus is 4-segmented including 1st segment immobile fused with tibia. The same in some Turbanoculata (see Index of characters [2.2.75], [], [2.2.83]).

(2) Maxillary palp has 3rd (distalmost) segment strongly diminished.

(3) Labial palp has 2nd segment widened inner-apically; 3rd (distalmost) segment is not large (Kluge 2004: Fig.26:D); the same in selected taxa of Turbanoculata (see Index of characters [1.1.58]).

(4) In subimago of both sexes most segments of all tarsi are covered with pointed microlepides, only 1st+2nd segment of middle and hind legs and on female fore leg [see (1)] is covered with microtrichiae, like tibia. The same in some Turbanoculata (see Index of characters [2.2.75], [], [2.2.83]).

Plesiomorphies of Siphlaenigma (unlike at least Turbanoculata). 

In imago and subimago: Eyes of male are not divided into two portions. Subimaginal sclerites of lateropostnotal crest and katepimeron are not elongate, not convergent (Kluge 2004: Fig.26:A). Furcasternal protuberances are contiguous. On fore wing MA forms a symmetrical fork near middle of wing; marginal intercalaries are absent; hind wing is well-developed, nearly as long as 0.3 of fore wing length, retains triads RS, MA, MP and veins CuA and CuP (Penniket 1962: Fig.1). On fore legs of male all 5 segments are long. Posterior projection of abdominal segment IX (i.e. styliger of male and postgenital plate of female) is large. Gonostylus has 2 distal segments. Penis is well-developed, with intrinsic muscle. Imaginal paracercus is well-developed, subequal to cerci. Ganglion of abdominal segment VIII separate from that of segment VII.

In larva: Kinetodontium is jointed, prostheca of both mandibles is brush-like (Kluge 2004: Fig.26:C). Larval mesonotum has a prominent relief repeating that of winged stages (unlike majority of Ephemeroptera); fore protoptera are not fused with apex of scutellum. Malpighian tubes are coiled. Unlike some specialized Turbanoculata, larva has siphlonuroid appearance – legs are able to stretch posteriorly; abdomen is able to make undulate movements; all tergalii I–VII are present; all three caudalii have dense primary swimming setae and have no secondary swimming setae. Unlike some Turbanoculata, setae proximad of prostheca are absent (Kluge 2004: Fig.26:C). Larval and adult patella-tibial suture is developed on middle and hind legs only (unlike larval Turbanoculata-Anteropatellata).

Size. Fore wing length 7–9 mm (see Tetramerotarsata).

Distribution. New Zealand.

Nominal species in Siphlaenigma/fg(1):

 edmundsi Lugo-Ortiz & McCafferty 1998 [Siphlaenigma] — syn.subj. janae [Siphlaenigma]

 janae Penniket 1962 [Siphlaenigma] ,/,//