CLADOENDESIS OF EPHEMEROPTERA
Heptagennota Pentamerotarsata Radulapalpata
Heptagenia/f5=g4 - Ecdyonurus/fg1)
Nomen hierarchicum: Ecdyonurus/fg1 [f:1905; g:1868] (incl. Afghanurus, Atopopus)
In circumscription fits:
gen. Ecdyonurus: Kluge 1983b: 16 (unpublished); 1988: 298
grex genn. Ecdyonurus: Tomka 1991: 121
tribus Ecdyonurini: Braasch 1990: 12
subfam. Ecdyonurinae: Wang & McCafferty 2004: 44
Ecdyonurus/fg1: Kluge 2004: 175
References. Bogoescu & Tabacaru 1968: * '; Kluge 1988: * *; Tomka 1991: *; Kluge 1993: * *; 2004: * * *.
Autapomorphies of Ecdyonurus/fg1.
(1) Metathoracic nerve ganglion is strongly transferred anteriorly, nearer to mesothoracic ganglion, being connected with it by a short unpaired connective. Due to this, imaginal and subimaginal median impression of furcasternum [see Heptagennota (4)] is not narrowed in anterior part (unlike all other Heptagennota), but is parallel-sided or widened toward its anterior part, where the metathoracic ganglion is situated (Kluge 2004: Fig.57:A-B).
(2) Mouth apparatus has following unique features.
Left and right mandibles [see Heptagennota (7)] have incisors dissimilar: incisor of left mandible (with mola projected distally) is pointed, with a row of denticles on inner margin; incisor of right mandible (with mola projected proximally) has a large denticle at some distance from apex and a row of smaller denticles proximad of it; denticles on outer margins of both incisors are at a distance from apex (Kluge 2004: Fig.58:B-C); in inversus [Ecdyonurus] the left and right mandibles are changed places (Kluge 1980: Fig.6768).
Superlingua [curved laterally see Heptagenia/f5=g4 (1)] has a peculiar shape uniform for all representatives: with a rounded apico-lateral projection (larger than in Heptagenia/f8=g7, more distinct than in Kageronia and Dacnogenia, and smaller than in Stenonema/g1), basally with a small rounded lateral convexity, lateral margin between this convexity and apico-lateral projection is slightly convex (Kluge 2004: Fig.58:D).
On maxilla (Kluge 2004: Fig.58:E-H) the ventral row of setae [see Branchitergaliae (1)] is transformed to a field of irregularly situated setae (unique apomorphy). Proximal dentiseta [see Bidentiseta (1)] is bifurcate.
(3) Tergalii are differentiated as following (Kluge 2004: Fig.57:D-E, 58:A): tergalius I is narrowed, with concave anal margin (i.e. has a more or less banana-like shape), that allows it to bend dorsally; tergalii IIVII are widened, with strongly convex anal margin i.e. have more or less roundish-triangular shape. Unique apomorphy.
(4) Outer (posterior) margin of larval femur [flattened see Heptagennota (1)] bears a regular row of long stout setae [unlike Heptagenia/f6=g5 see Kageronia (4) and Heptagenia/f7=g6 (2)]. These setae are situated less dorsally, than similar setae in Rhithrogena/fg1 and Cinygma. Non-unique apomorphy: regular row of setae on outer margin of femur appeared independently in various rheophilous mayflies.
Characters of Ecdyonurus/fg1 of unclear phylogenetic status.
(5) 2nd+3rd segment of labial palp [specialized as scraping see Radulapalpata (1)] is pointed, thus field of scraping setae terminates at a distance from end of sclerotized ridge (Kluge 2004: Fig.57:H). The same in Kageronia and Rhithrogena/fg1; probably symplesiomorphy. In Heptagenia/f7=g6 and Cinygma form of this segment is different.
(6) Tergalius VII [see (3)] nearly always lacks fibrillose lobe [see Branchitergaliae (3)] (thus fibrillose lobe is present only on tergalii IVII, rarely IV); only in selected species (particularly in Ecdyonurus/fg2 insignis [H.]) tergalius VII has fibrillose lobe (probably secondarily restored).
Size. Fore wing length 518 mm.
Age and distribution. Palaeogene (see Nestormeus) recent; Arctogea (Holarctic + Oriental + Afrotropical Regions); dominate in Holarctic.
|The taxon Ecdyonurus/fg1 is divided into:|
2.2.1. Plesiomorphon Afghanurus/g2
22.214.171.124. plesiomorphon Ecdyogymnurus
Leucrocuta/f1=Afghanurus/g1 incertae sedis
3.1. plesiomorphon Thamnodontus
Some insufficiently described Asian and African taxa have uncertain systematic position