CLADOENDESIS OF EPHEMEROPTERA |
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Dicercomyzon
(Panephemeroptera
Euephemeroptera
Euplectoptera
Anteritorna
Bidentiseta
Furcatergaliae
Ephemerella/fg1
Pantricorythi
Tricoryptera
Afrotricorythi
-
Dicercomyzon)
Nomen hierarchicum: Dicercomyzon/fg(1)
[f:1954; g:1954]
In circumscription fits:
— gen. Dicercomyzon Demoulin 1954a: 1
— subfam. Dicercomyzinae Edmunds & Traver 1954a: 238
— Dicercomyzon/fg(1): Kluge 2004: 332
References. Demoulin 1954a: ;
– 1954d:
; – Kimmins 1957:
; – Edmunds & Allen &
Peters 1963:
; – Demoulin 1964b:
; – Kluge 2004:
*
*
*
Autapomorphies of Dicercomyzon. (1) Larval head is prognathous,
frons forms a shield covering mouthparts from above
(2) Mouth apparatus is strongly modified (Demoulin 1964b: Fig.4–5): Mandibles are shortened perpendicular to axis of articulation. Superlinguae are stretched laterally. Maxilla [with vestigial palp – see Ephemerella/fg1 (1)] has a unique structure, being strongly specialized as scraping: short and stout; field of closely situated setae on apical-ventral side [see Ephemerella/fg1 (16)] is greatly enlarged and occupies largest part of maxilla; maxillary canines are lost; only 1 dentiseta is retained [instead of two – see Bidentiseta (1)] (Demoulin 1964b: Fig.5D). Labium is strongly widened, with widened paraglossae. (3) Larval sterna form two roundish disks, the anterior of which overlaps by its posterior margin the posterior one; margins of these disks are fringed by dense setae; the anterior disc is formed by sternites of prothorax and mesothorax, and the posterior one – by sternites of metathorax, abdominal segment I and partly segment II (Demoulin 1964b: Fig.3A). Probably these disks are used as adhesive suckers. Similar disk on sterna is present in Ephemerella/fg4 Drunella/g1 doddsi [E.], but there it is formed by abdominal sterna II–IX. (4) Each tergalius [II–VI – see Tricoryptera (5) and (6)] consists of a single lamella with numerous long processes on margins (Demoulin 1964b: Fig.3B-F). Such tergalius sharply differs from the initial one [see Ephemerella/fg1 (7)]; probably it is formed by complete fusion of initial two branches of ventral lobe, while dorsal lobe is completely lost. In some other Ephemerella/fg1 branches of ventral lobe can be fused, but dorsal lobe never has tendency to reduction or loss. (5) Larval, subimaginal and
imaginal paracercus is vestigial, non-segmented
(6)
Larval body
is short, and femora are strongly widened, flat, nearly round; together with
large flat frontal shield [see (1)], body and legs form a nearly round disk
Characters of Dicercomyzon of unclear phylogenetic status. (7) On fore wing marginal intercalaries are absent. Among Ephemerella/fg1 the same in Tricorygnatha and Leptohyphes/fg1 (see Index of characters [2.2.55]); possibly synapomorphy. (8) Hind wings [initially vestigial – see Tricoryptera (2)] are lost. Non-unique apomorphy (see Index of characters [2.2.59]). (9) In male imago fore leg is not elongate. The same in Tricorygnatha and some others (see Index of characters [2.2.74]). On all legs tarsal segments 1–4 are extremely shortened. Plesiomorphies of Dicercomyzon. Eyes of male are large. Imaginal and subimaginal mesonotum [without outlined lateral pigmented area – see Tricoryptera (4)] retains curved lateroparapsidal suture [see Ephemerella/fg1 (10)] and has no transverse interscutal suture (Kluge 2004: Fig.99:D) (unlike Tricorygnatha and some others – see Index of characters [2.2.9] and [2.2.10]). Imaginal wing without setae on amphitornal margin (unlike Tricorygnatha and Leptohyphes/fg1). At rest, subimago and imago keep wings raised up (unlike Tricorygnatha and some others). Claws on fore leg of male imago are ephemeropteroid (as well as other claws of imago and subimago – see Plesiomorphies of Ephemerella/fg1). |
Size. Fore wing length 4–6 mm (see Tricoryptera).
Distribution. Afrotropical Region.
Nominal species in Dicercomyzon/fg(1):
costale Kimmins 1957 [Dicercomyzon]
— syn.subj. femorale
[Dicercomyzon]
femorale
Demoulin 1954 [Dicercomyzon]
-
-
/
marginatum Kimmins 1957 [Dicercomyzon]
— syn.subj. sjostedti [Caenis]
sjostedti Ulmer
1910 [Caenis]
-
-
/
verrierae
Demoulin 1964 [Dicercomyzon]
Examined also:
See also:
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