CLADOENDESIS OF EPHEMEROPTERA

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z 

Autapomorphies of Petersula/g2.

(1) Labrum contains a pair of muscles-depressors located at midlength of the labrum and at equal distances from lateral margins of the labrum and one from another (Kluge et al. 2022: Fig.106). Each muscle-depressor represents a compact cylindrical bunch of myofibrils passing across the labrum from dorsal to ventral surface perpendicular to the surfaces (ibid.: Fig.101). Externally, places of their attachment on the dorsal side are visible as a pair of small round spots, either lighter than background (if cuticle of the labrum is dark—ibid.: Fig.96), or darker than background (in transmitted light, if the cuticle is light—ibid.: Figs 106–107). In other mayflies such paired, well-outlined and widely separated labral depressors are not found; if the labral depressor is present, it is unpaired and located close to the labrum base. In representatives of Kimminsula/g1 other than Petersula, labral depressors are not found at all.

(2) Prostheca of each mandible lacks plumose branch directed proximally, with few (6–8) slender branches instead of it (Kluge et al. 2022: Figs 108–110) (in contrast to other Kimminsula/g1 and ???).

(3) Maxillary palp [see Kimminsula/g1 (6)]. Long setae on inner side of 2nd segment form a compact tuft near apex; proximad of it, there is a longitudinal row of very short setae ((Kluge et al. 2022: Fig.111) (in contrast to other Kimminsula/g1).

(4) Patella-tibial suture is modified as follows: on all legs of larva it is present, but incomplete, i.e. not reaching inner side of the tibia (Kluge et al. 2022: Figs 124, 126–128); in subimago and imago of both sexes patella-tibial suture is not expressed (Kluge et al. 2022: Figs 159–161, 162–164, 212–214). This differs from all other Leptophlebiidae, where patella-tibial suture is absent on forelegs at all stages of development; among all Ephemeroptera, this suture is present on forelegs only in the baetid taxon Anteropatellata and in the heptageniid taxon Rhithrogena/fg3 (see Index of characters [1.2.18]). Besides Petersula, larval patella-tibial suture is incomplete on hind legs of Kimminsula/g3. Besides Petersula, patella-tibial suture of subimago and imago is absent in some other taxa, including Kimminsula/g3 and Hubbardula.

(4) Apex of each paired penis lobe bears a pointed process directed medially-ventrally; this process has a shape of rolled plate (C-shape in cross section) faced by its groove laterally-ventrally-apically; gonopore is located on medio-dorsal side of the penis lobe, proximad of place where the pointed process is attached (Kluge et al. 2022: Figs 172–173, 179–181, 182–183). Gonoducts proximad of the penis are soft and do not form capsules of regular shape (ibid.: Fig. 183) (in contrast to Ceylonula).

Subimago has the same penis structure. Subimaginal cuticle of the penis, including the pointed projections, is colorless and non-sclerotized, does not retain its shape on shed exuviae (ibid.: Fig. 185).

Protopenis of larva bears precursors of the pointed processes and precursors of the gonopores (ibid.: Figs 175–177, 209). The precursors of pointed processes arise from apices of the protopenes and are directed medially-ventrally; in contrast to imago and subimago, they are not grooved. The precursors of gonopores are represented by a pair of small fossae on dorsal sides of the protopenes.

Among Kimminsula/g1, medio-ventral pointed processes of other shapes are present in Ceylonula and Kinninsula/g3; their larval protopenes have no precursors of these processes; Hubbardula has no medio-ventral processes in any stage of development; imaginal genitalia of Ghatula are unknown.

Characters of Petersula/g2 of unclear phylogenetic status. 

(5) Mandible [see Kimminsula/g1 ()] has no middle tuft of setae on outer margin, i.e. with sparse setae evenly arranged on the outer margin laterad of the distal setal tuft (Kluge et al. 2022: Figs 145–146) (in contras to other Kimminsula/g1).

 (6) In larva, tibia of each leg pair bears two longitudinal rows of hair-like setae: one row just on outer side, another row anteriad of it (among Kimminsula/g1, the same in Kimminsula/g3 and Hubbardula, in contrast to Ghatula and Ceylonula); each row is nearly regular, i.e. mostly with one seta in section (Kluge et al. 2022: Figs 124–125).

Plesiomorphies of Petersula/g2.

(7) Hind wing [see Kimminsula/g1 ()] has vein MP bifurcate (in contrast to Ghatula); its bifurcation either forms a triade with longer or shorter intercalary (Kluge et al. 2022: Figs 153, 157), or lacks intercalary (ibid.: Figs 139, 217), or with two branches fused apically and forming a closed cell (ibid.: Fig. 158).