CLADOENDESIS OF EPHEMEROPTERA

ABC

z 

Baetisca/f3=g2

(Panephemeroptera Euephemeroptera Euplectoptera Posteritorna  
Baetisca/f2=g1 - Baetisca/f3=g2)

Nomen hierarchicum: Baetisca/f3=g2 [f:1900; g:1862] (sine Balticobaetisca; incl. Fascioculus).

In circumscription fits: 

gen. Baetisca Walsh 1863: 378

tribus Baetiscini Banks 1990: 246

subfam. Baetiscinae: Needham & Traver & Hsu 1935: 555

fam. Baetiscidae: Edmunds & Traver 1954a: 240

superfam. Baetiscoidea: McCafferty 1991a: 349

Baetisca/f3=g2: Kluge 2004: 69


References. Eaton 1883-1888: * *; Needham & Traver & Hsu 1935: * *; Edmunds & Allen & Peters 1963: *; Tshernova 1970: * *; Edmunds & Jensen & Berner 1976: * *; Berner & Pescador 1980; Pescador & Berner 1981: * *; Staniczek & Bechly 2002: * Kluge 2004: * * *.


Autapomorphies of Baetisca/f3=g2.

(1) In imago abdominal tergum VI [enlarged see Posteritorna (5)] has mid-dorsal elevation with transverse crest, similar to that of larva. 

(2) In female imago pos`terior margin of abdominal sternum IX produces a pair of projections with a median cleft between them (Pescador & Peters 1974: Fig.25C). Non-unique character, the same in many other mayflies (but not in Balticobaetisca). 

Characters of Baetisca/f3=g2 of unclear phylogenetic status (unknown for Balticobaetisca).

(3) 2nd (penultimate) segment of labial palp has apical projection on inner side (Eaton 1883-1888: Pl.52:9; Pescador & Peters 1974: Fig.15E). Non-unique apomorphy (see Index of characters [1.1.58]); as mouth apparatus of Prosopistoma/f1=g2 is strongly modified, it is not clear if this is an apomorphy of Baetisca/f2=g1 or Posteritorna in general.

(4) Larval notal shield [see Posteritorna (3)] has a pair of lateral projections, which in different species have shape from small blunt protuberances to large pointed spines (Pescador & Berner 1981: Fig.10-14); they can increase from instar to instar (Pescador & Peters 1974: Fig.10,11,14).

(5) On fore legs of male imago and subimago both claws are blunt (Pescador & Peters 1974: Fig.24C). Non-unique apomorphy (see Index of characters [2.2.77]); possibly this is an apomorphy of Posteritorna in general, because Prosopistoma/f1=g2 has more simplified claws [see Prosopistoma/f1=g2 (4) above].

Size. Fore wing length 616 mm.

Distribution. Nearctic (dominate in Eastern Nearctic).


The taxon Baetisca/f3=g2 is divided into:

1. Fascioculus

2. Baetisca/f4=g3