CLADOENDESIS OF EPHEMEROPTERA

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Stenacron

(Panephemeroptera Euephemeroptera Euplectoptera Anteritorna Bidentiseta Branchitergaliae
Heptagennota Pentamerotarsata Radulapalpata 
Heptagenia/f5=g4
Ecdyonurus/fg1Heptagenia/f6=g5KageroniaHeptagenia/f7=g6  
Stenonema/fg1 - Stenacron)

Nomen hierarchicum: Stenacron/g(1) [g:1974]

In circumscription fits:

— grex spp. interpunctata: Spieth 1933: 332

— grex spp. interpunctatum: Traver 1933: 173

— subgen. Stenacron: Kluge 1983b: 16 (Abstract)

— gen. Stenacron Jensen 1974: 225

— Stenacron/g(1): Kluge 2004: 173


References. Spieth 1933: *; – Spieth 1947: * * *; – Koss 1968: *; – Jensen 1974: * *; – Edmunds & Jensen & Berner 1976: * *; – Kluge 2004: * * * *.


Autapomorphy of Stenacron.

(1) Egg, instead of usual knob-terminated threads [see Branchitergaliae (4)], bears on each pole a ring formed by very long coiled threads, that looks as a polar cap (Koss 1968: Fig.16). Similar structure occurs in some Furcatergaliae only (see Index of characters [3.6]).

Character of Stenacron of unclear phylogenetic status.

(2) All tergalii I–VII have stretched pointed apices, and tergalii I–VI [which have long anal rib – see Stenonema/fg1 (2)] have this pointed apex somewhat curved anteriorly (Kluge 2004: Fig.56:O). In all other Stenonema/fg1 tergalii I–VI are not pointed.

Plesiomorphy of Stenacron. Unlike Macdunnoa, tergalii VII [thin and lacking fibrillose portion – see Stenonema/fg1 (3)] are not shortened.

Size. Fore wing length 8–12 mm. 

Distribution. Eastern Nearctic.


Nominal species in Stenacron/g(1):

affine Traver 1933 [Stenonema] — syn.subj. interpunctata [Baetis]

areion Burks 1953 [Stenonema] — syn.subj. interpunctata [Baetis]

canadensis Walker 1853 [Baetis] — syn.subj. interpunctata [Baetis]

candidum Traver (in Needham & Traver & Hsu) 1935 [Stenonema]

carolina Banks 1914 [Heptagenia]

conjunctum Traver (in Needham & Traver & Hsu) 1935 [Stenonema] — syn.subj. interpunctata [Baetis]

floridense Lewis 1974 [Stenonema]

frontale Banks 1910 [Heptagenia] — syn.subj. interpunctata [Baetis]

gildersleevei Traver (in Needham & Traver & Hsu) 1935 [Stenonema]

heterotarsalis McDunnough 1933 [Ecdyonurus] — syn.subj. interpunctata [Baetis]

interpunctata Say 1839 [Baetis] — typus nominis Stenacron ,,/

majus Traver (in Needham & Traver & Hsu) 1935 [Stenonema] — syn.subj. interpunctata [Baetis]

minnetonka Daggy 1945 [Stenonema]

ohioense Traver (in Needham & Traver & Hsu) 1935 [Stenonema] — syn.subj. interpunctata [Baetis]

pallidum Traver 1933 [Stenonema]

proximum Traver (in Needham & Traver & Hsu) 1935 [Stenonema] — syn.subj. interpunctata [Baetis]


See also:

Radulapalpata INCERTAE SEDIS

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