Parasialidae Ponomarenko, 1977

Shcherbakov, Dmitry E., 2013, Permian ancestors of Hymenoptera and Raphidioptera, ZooKeys 358, pp. 45-67 : 48-49

Family Parasialidae Ponomarenko, 1977

Diagnosis.

Medium-sized insects (wings 6.5-17 mm long). Sc joining base of pterostigma; RP origin rather distal; RP and MA deeply forked; rp-ma crossvein present; MP once forked (much beyond R fork). Free base of MA developed as crossvein originating from M stem. Anal area at least 1/2 wing length. In forewing, RP+MA angled forwards at base of pterostigma, M and CuA forming long anastomosis (ending nearly level to R fork), M arched forwards distad of anastomosis, free base of MA just beyond M+CuA fork, and CuA forked. In hind wing (Fig. 6), M and CuA connected by very oblique arculus, CuA simple, and anal area variable (narrow in smaller species and broadened in larger species). Nygmata present. Veins and wing membrane evenly covered with short hairs. Short-bodied, somewhat dorsoventrally depressed. Head large, markedly transverse. Pronotum small, very short; pterothorax homonomous; legs short. Abdomen rather short, with short, well sclerotized segments. Male genitalia without prominent genital capsule, gonocoxites directed caudad, clavate gonostyles directed mediad.

Composition.

Parasialis Ponomarenko, 1977 (Lower to?Upper Permian of Eurasia; 4 species; Figs 1, 5, 7, 8), Sojanasialis Ponomarenko, 1977 (Middle Permian of Soyana; monobasic).

Remarks.

In the wing structure Parasialidae are similar to Sialidae , but in the latter the R and MP forks are more proximal in the forewing, and the nygmata are absent.

The hind wings of Parasialidae differ from the forewings in the basal mcu crossvein (arculus) developed instead of M+CuA anastomosis, and CuA unbranched. The hind wing anal area is expanded, with up to six unbranched anal veins in larger parasialids, but relatively small in the smallest parasialid, Parasialis rozhkovi (likewise in Sialidae the extent of the hind wing anal area depends on the body size and abdomen mass, so that e.g. in males of smaller species of Indosialis the fore and hind wings have anal areas of equal size).