CLADOENDESIS OF EPHEMEROPTERA
Heptagennota Pentamerotarsata Radulapalpata
Nomen hierarchicum: Stenonema/fg1 [f:2004; g:1933] (incl. Stenacron, Macdunnoa)
In circumscription fits:
grex subgenn. Stenonema: Kluge 1988: 287
gen. Stenonema Traver 1933: 173
Stenonema/fg1: Kluge 2004: 173
References. Traver 1933: *; Needham & Traver & Hsu 1935: *; Spieth 1947: *; Lewis 1974: ; Tshernova 1976: *; Kluge 1988: *; 1993: *; 2004: * * * *.
Autapomorphies of Stenonema/fg1.
(1) Superlingua [curved laterally see Heptagenia/f5=g4 (1)] is especially sharply curved and stretched laterally; by its form differs from any other taxon among Heptagenia/f5=g4 (Kluge 1988: Fig.16).
(2) On tergalii IVI costal rib is lost, and anal rib [initially situated on anal margin see Branchitergaliae (3)] is situated at a distance from anal margin, being especially long and nearly straight (Kluge 2004: Fig.56:O). Unique apomorphy.
(3) Tergalii VII are vestigial, lack fibrillose ventral lobe, thus fibrillose lobe [see Branchitergaliae (3)] is present on tergalii IVI only. Non-unique apomorphy (see Index of characters [1.3.59]); among Heptagenia/f5=g4 fibrillose lobe of tergalius VII is lost also in Kageronia and majority of Ecdyonurus/fg1.
Characters of Stenonema/fg1 of unclear phylogenetic status.
(4) Glossae [initially pyramidal see Radulapalpata (1)] with straight or slightly curved inner margin, with distal half flattened, as dorsal edge is approximated to median edge (Kluge 2004: Fig.56:I-J,N). The same in Heptagenia/f8=g7; probably, synapomorphy.
Variable characters of Stenonema/fg1. In selected species of Stenacron and Stenonema/fg3 in imago and subimago on fore tarsus 1st segment can be shortened (like in Heptagenia/f8=g7) or not shortened.
Size. Fore wing length 616 mm.
Distribution. North and Central America (dominate in Eastern Nearctic).
|The taxon Stenonema/fg1 is divided into:|