Strivicia, SHCHERBAKOV, 2022

SHCHERBAKOV, DMITRY E., 2022, A new genus of Ipsviciidae (Hemiptera, Cicadomorpha) with a tegminal strigil from the Triassic of Madygen, Palaeoentomology 5 (5), pp. 434-438 : 434

Strivicia gen. nov.

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Type species. Strivicia davidi sp. nov.; by present designation.

Included species. Type species.

Etymology. From Latin stridulus (creaking, grating) and the genus Ipsvicia ; gender feminine.

Diagnosis. Tegmen small, length less than 5 mm, weakly elongate, widest before midlength, tapered beyond; postclaval margin convex; costal area distal to costal fracture sloped ventrally, with finely striate strigil; bSc deeply arched; R stem short; dSc sigmoidal, moderately long, reaching at most 1/2 tegmen length; both R stem and dSc convex; R distal to dSc with 3 anterior branches; M and CuA beyond short triangular basal cell fused for some distance, then divergent up to ~1/2 tegmen length, medial area lanceolate; single crossvein r-m; posterior M branch fused to CuA 1; 7 apical cells; ocellate spots in radial and medial areas.

Remarks. Distinct from all known ipsviciids in the presence of a strigil. The new genus is more primitive than the Late Triassic genera Ipsvicia Tillyard, 1919 and Ipsviciopsis Tillyard, 1922 , but is similar to these latter in the tegmen shape, deeply arched bSc, long sigmoidal dSc, lanceolate medial area, and distal R branches in an anterior pecten opposed to the posterior M+CuA pecten. The two latter genera have more elongate tegmina with a straight postclaval margin aligned with the commissural margin, horizontal costal area, concave R stem, concave longitudinal dSc reaching beyond 1/2 tegmen length, 2 or 3 crossveins r-m, and more numerous apical cells. The new genus is similar to the Middle Triassic (Anisian) genus Triassophyllum Papier, Nel, Grauvogel-Stamm & Gall, 1997 ( Fig. 1 ; described in Orthoptera , later transferred to Ipsviciidae ; Shcherbakov in Gorochov, 2005; Lambkin, 2020) in the moderately long dSc and presence of ocellate spots in the radial and medial areas, but in the latter genus tegmina are much larger, with rich venation, numerous crossveins and dSc originating more distally and reaching beyond 1/2 tegmen length. Strivicia gen. nov. is distinct from incompletely known Triassic genera Ipsvicioides Fujiyama, 1973 , Doryscarta Lin, 1982 , and Shaanxioscarta Lin, 1982 , and the Early Jurassic genus Ipsviciella Becker-Migdisova, 1962 at least in only three anterior branches on R distal to dSc and the shape of tegmen.

Figures

FIGURE 1. Triassophyllum leopardii Papier, Nel, Grauvogel-Stamm & Gall, 1997, tegmina (images flipped). A, Specimen no. 7882 (Papier et al., 1997, fig. 2B–D; arrows, costal fracture and dSc). B, Specimen no. 9116. Scale bars = 5 mm.