Sigmaboilus longus, 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 : 60-61

Sigmaboilus longus sp. nov.

Fig. 3

Diagnosis. Based on female tegmen only. Tegmen oblong, C extremely long (far beyond first branch of RA), and crossing most branches of Sc; RA and RS pectinate with 4 anterior and 7 posterior branches, repectively; MA2 originating at about the same level of fusion point of MP and CuA1; MP+CuA1 with 6 terminal branches; CuP slightly Z-shaped, and very close to stem CuA for basal 1/3 length; 1A running close and parallel to CuP; area between CuP and 1A much narrower than between 1A and 2A.

Description. Isolated left tegmen large, preserved length 55.8 mm, total length about 59 mm, width 16.3 mm, ratio of length to maximal width about 3.62. C very long, almost reaching the same level of second branch of RA, and crossing most branches of Sc; precostal area broad with numerous radial veinlets; Sc nearly straight, ending in anterior margin at basal 4/5 tegminal length with numerous branches; RA and RS diverging at 22.5 mm distal of tegminal base with RA pectinately 4-branched and RS 7-branched; MA and MP diverging at 16.8 mm distal of tegminal base; stem MA short, and forking into MA1 and MA2 at 14.6 mm distal of tegminal base; both MA1 and MA2 simple and arched; stem MP fused with CuA1 slightly basal of MA bifurcation; MP and CuA1 fused for a short interval and then branched just opposite the MA bifurcation; stem MP+CuA1 exhibiting 6 terminal branches. CuP slightly Z-shaped, and very close to CuA for basal 1/3 length; 1A and 2A strong, and area between 1A and 2A broad. Crossveins arranged in second intercalary pseudoveins in posterior and subdistal area of tegmen (area between branches of RS, and between MA and MP+CuA1). The pigmentation seems to be interrupted and form inrregular bands on the whole tegmen.

Etymology. The specific epithet is from Latin longus , in reference to the long stem C in tegmina.

Holotype. NIGP 148113a and NIGP 148113b, part and counterpart, female tegmen with precostal area slightly damaged.

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

Remarks. This species differs from the above two ones in having a tegmen with C much longer (almost reaching the same level of the second branch of RA). It further differs from S. gorochovi in having a tegmen with pigmentation like incontinuous bands, and from S. sinensis in the tegmen with RA possessing much fewer branches.

Figures

FIGURE 3. Sigmaboilus longus gen. et sp. nov., female tegmen, holotype, NIGP 148113 a. Photograph (print; dry and under alcohol) and reconstruction. Scale bar represents 10 mm.