Sigmaboilus Fang, Zhang & Wang, 2007

Gu, Junjie, Zhao, Yun-Yun & Ren, Dong, 2009, New fossil Prophalangopsidae (Orthoptera, Hagloidea) from the Middle Jurassic of Inner Mongolia, China, Zootaxa 2004, pp. 16-24 : 17

Genus Sigmaboilus Fang, Zhang & Wang, 2007

Type species: Sigmaboilus gorochovi Fang, Zhang & Wang, 2007

Revised diagnosis: Forewing: Base of tegmen constricted; ScA long, mildly undulate, reaching anterior wing margin beyond midlength; ScP long with numerous branches ending in stem ScA; Cross-veins at the base of area between CuA+M and CuP sigmoidal; CuA and CuP1a remaining united as CuA+CuP1a for a short and appreciable distance.

Hindwing: ScP and R with basal common stem, basal free part of R slightly curved; R diverging nearer wing base than in forewing, RP branched before first branch of RA; M bowed toward R and diverging before origin of RP.

Species included: S. gorochovi Fang, Zhang & Wang, 2007 , S. sinensis Fang, Zhang & Wang, 2007 , S. fuscus sp. nov. S. peregrinus sp. nov.

Remarks: The genus Sigmaboilus Fang, Zhang & Wang, 2007 was erected based on only a single forewing from the Middle Jurassic of Daohugou, Inner Mongolia, China. The diagnostic characteristics of the hind wing can be seen clearly from the material described here: ScP fused with R at base, separated before the point of origin MA.