Sigmaboilus sinensis, Fang, Yan, Zhang, Haichun, Wang, Bo & Zhang, Yutao, 2007

Fang, Yan, Zhang, Haichun, Wang, Bo & Zhang, Yutao, 2007, New taxa of Aboilinae (Insecta, Orthoptera, Prophalangopsidae) from the Middle Jurassic of Daohugou, Inner Mongolia, China, Zootaxa 1637, pp. 55-62 : 58-59

Sigmaboilus sinensis sp. nov.

Fig. 2

Diagnosis. Based on male tegmen. Eleven branches of Sc ending in longitudinal stem C; RA and RS pectinate, repectively 6- and 7-branched; origin of MA2 at about the same level of fusion point of MP and CuA1; MP+CuA1 having 6 terminal branches; “handle vein” slightly curved; crossveins between “handle vein” and CuA1 regularly arranged with last one ending in “handle vein”.

Description. Isolated right tegmen spindle-shaped, length 39.5 mm, width 10.3 mm, ratio of length to maximal width 3.83. Costal area very broad, occupied by numerous “radial veinlets”, close to each other basally and arranged in secondary intercalary pseudoveinlets; C slightly sigmoidal, and reaching anterior margin of tegmen slightly distal of first branch of RA; Sc straight, ending in anterior margin at basal 3/4 tegminal length and issuing 15 branches, of which basal 11 are strongly oblique and teminate in longitudinal stem C. Area between Sc and R very narrow; RA and RS diverging at about 1/3 basal tegminal length with RA pectinately 6-branched and RS 7-branched; origin of RS at 12.7 mm distal of tegminal base; MA and MP diverging at about basal 1/4 tegminal length; stem MA short, and forking into MA1 and MA2 at 10.2 mm distal of tegminal base; both MA1 and MA2 simple and arched; MP meeting CuA1 at 10.8 mm distal of tegminal base. Area between R and MA broad, and area between M and CuA1 very narrow. After meeting as MP+CuA1, MP and CuA1 united for a short but appreciable distance, and then divided into 6 terminal branches. Stridulatory vein strong; crossveins between base of MP+CuA1 and CuA2 slightly curved; “oblique veins” (crossveins between CuA and CuP) slightly curved; “handle vein” slightly curved, subparallel to the nearest crossvein between last branch of MP+CuA1 and CuP. Crossveins between “handle vein” and CuA regularly arranged with last one ending in “handle vein”. CuP strongly curved and Z-shaped, 1A similar to CuP in shape, very close to and touching CuP at a point. Area between 1A and 2A much broader than that between CuP and 1A. Pigmentation is present on most of the tegmen, and seems to form indistinct transverse bands on the distal half.

Etymology. Specific name is from Latin sina, meaning China.

Holotype. NIGP 148112, male tegmen, slightly damaged.

Age and occurrence. Middle Jurassic; Daohugou village, Ningcheng County, Chifeng City, Inner Mongolia, China.

Remarks. The new species differs from S. gorochovi in having a tegmen with 11 branches of Sc ending in C (8 for the latter), “handle vein” and each crossvein between “handle vein” and CuA1 forming a distinct angle (subparallel to each other for the latter), MP+CuA1 exhibiting a different branching mode, and transverse bands on the distal half of tegmen (fuscous on the whole tegmen for the latter).

Figures

FIGURE 2. Sigmaboilus sinensis gen. et sp. nov., male tegmen, holotype, NIGP 148112. Photograph (print; dry and under alcohol) and reconstruction. Scale bar represents 10 mm.