Crosbella Evans, 1956

Lambkin, Kevin J., 2020, Revision of the Hylicellidae of the Late Triassic of Queensland (Hemiptera Cicadomorpha: Hylicelloidea), Zootaxa 4790 (3), pp. 525-539 : 528

Crosbella Evans, 1956

Crosbella Evans, 1956: 192 .

Type species. Crosbella elongata Evans, 1956 , by original designation.

Mesocicadella Evans, 1956: 193 , syn. nov.

Type species. Mesocicadella venosa Evans, 1956 , by original designation.

Emended diagnosis. Tegmen almost 3.5 times longer than wide; except for extreme apical area, entirely somewhat coarsely punctate; costal margin broadly convex proximally, almost straight distally, apex broadly rounded (appearing narrowly rounded in the holotype of the type species ( Figs 4, 5 ), but the specimen is longitudinally convexly curved on the rock surface); peripheral membrane noticeably wider at CuA; bSc not detected; costal space c. 2 times as wide as medial cell, with 3–5 faint, sometimes branched, incompletely developed costal veinlets; R and M separating near apex of basal cell; basal cell parallel-sided, closed distally by a fusion of M and CuA at a single point; R fork just before tegmen length, a short distance proximal to M fork; CuA fork just distal to R fork and proximal to M fork; RA fork distal to M fork; post-nodal venation complex, much proliferated in both branching and crossveins, and quite variable between specimens; RA 1 oblique; RA multi-branched and tending to pectinate, with 6–8 terminations and occasional crossveins, occupying entire antero-apical margin; up to 3 ir; RP multi-branched, with up to 6 or possibly more terminations; 2 or 3 r-m; M multi-branched, with 7–9 terminations and 3 or 4 im; intra-medial cell (including accessory crossveins) long and narrow, c. 5 times longer than wide, occupying a small portion of postnodal area; 2–4 m-cua; basal piece of CuA 1 before 1 st m-cua long, oblique and almost parallel with margin, CuA 1 then multi-branched, tending to pectinate, with up to 5 terminations and the occasional crossvein, CuA 1b (simple or with one fork) more or less parallel with the short and simple CuA 2; basal CuA 1 cell thus quite broad and parallelogram-like; apical crossvein fields random, not aligned; clavus not preserved.

Notes. Crosbella was assigned by Evans (1956) to the Scytinopteridae (which was more or less the fossil hemipteran catch-all family, prior to its redefinition by Shcherbakov (1984)), by Becker-Migdisova (1962a) and Carpenter (1992) to the fulgoromorph family Pereboriidae (this family transferred to the Cicadomorpha by Shcherbakov (1984)), and by Jell (2004) to the Scytinopteridae . Mesocicadella was considered in Scytinopteridae by Evans (1956), Pereboriidae by Becker-Migdisova (1962a), and as ‘Family uncertain’ by Carpenter (1992) and Jell (2004). Both genera were transferred to Hylicellidae by Hamilton (1992). On the basis of the proliferated and variable apical venation, the presence of weakly developed costal veinlets, and the fusion of M and CuA at a single point to close the basal cell, Crosbella is assigned to subfamily Vietocyclinae . Shcherbakov (1988) noted that both the size and venation of the vietocycline tegmen are highly variable. Crosbella differs from the two other vietocycline genera, Cycloscytina and Vietocycla , in the CuA fork proximal to the M fork, the broad and parallelogram-like CuA 1 cell, and the multibranched CuA 1 ( Shcherbakov 1988, figs 3b, 3c: Fu & Huang 2019).

Figures

FIGURES 4–6. Crosbella elongata Evans: 4, holotype UQC2125 (mirrored); 5, holotype and postero-apical area of holotype UQC174 of Crosbella alata Evans; 6, holotype UQC174 of C. alata.