A new species of Fuziidae (Insecta, Blattida) from the Inner Mongolia, China

Abstract A new species attributed to the genus Parvifuzia Guo & Ren, 2011, Parvifuzia peregrina sp. n., is described from the Middle Jurassic Jiulongshan Formation of Daohugou Village, Inner Mongolia, China. This new species, with apex of wing almost reaching the end of the abdomen and forewing venation with 30–32 veins at margin, broadens the diversity of Parvifuzia. This new species, with strongly curved cerci, could tightly clasp female and complete copulation more efficiently, same as other members of the family Fuziidae.

This family is only found in the Middle Jurassic of China so far. It might have originated during the Triassic and became extinct in the Late Jurassic ). This family is distinguished by its unique structure of male's elongated body and forceps of earwig-like cerci (attached to the external ovipositor during courtship).
Recently we collected three well-preserved fossils of Fuziidae from Jiulongshan Formation in Daohugou Village, Ningcheng County, Inner Mongolia, China. After detailed examination, we consider these specimens belonging to the genus Parvifuzia based on the following features: small-sized (body length 10.4-10.6 mm and forewing length 8.5-8.8 mm); apex of cerci strongly curved inward, with a narrow gap at the center; wing venation simple; forewing R strongly curved, CuA almost straight, then curved to posterior wing margin.

Material and methods
Three specimens of the new species are deposited in the fossil insect collection of the Key Laboratory of Insect Evolution & Environmental Changes, Capital Normal University, Beijing, China. The specimens were examined with a Leica MZ 12.5 dissecting microscope and illustrated with the aid of a drawing tube attached to the microscope. Line drawings were made with Photoshop CS 8.0 graphic software. Photographs of fossils were taken by a MZ12.5 dissecting microscope (Leica, Wetzlar, Germany), either dry or with alcohol.
The venation nomenclature used in this paper is based on the interpretation of Vršanský (1997 Guo & Ren, 2011 Other species included. P. brava Guo & Ren, 2011, and P. peregrina sp. n.  Guo & Ren, 2011 in the following aspects: small-sized; apex of cerci strongly curved inward and rounded in shape, with a narrow gap at the center; wing venation simple; forewing R strongly curved like waves, CuA almost straight, then curved to posterior wing margin, anal area wide.

Key to species of the genus Parvifuzia
However, P. peregrina sp. n. can be easily differentiated from the other two previously described species: apex of wing almost reaching the end of the abdomen in P. peregrina sp. n. vs. apex of wing just reaching the middle of the 8 th abdominal segment; forewing length is longer (forewing length 8.5-8.8 mm in P. peregrina sp. n., vs. forewing length 6.3-6.4 mm); and forewing venation with 30-32 veins at margin in P. peregrina sp. n., vs. forewing venation with 25-27 veins at margin.
Forewings (Figs 1, 2, 3B): length range about 8.5-8.8 mm, width range about 2.6-2.9 mm; narrow, without coloration, with intercalaries and wing venation simple, with 30-32 veins at margin; costal area wide (1/3 width of the wing); Sc simple, curved upward, longer than clavus; R strongly curved like waves and with 9-14 branches, reaching the anterior wing margin; M slightly curved and with 5-7 branches, most posterior branch of M reaching wing apex; CuA almost straight to posterior wing margin and with 5-8 branches; CuP strongly curved and simple; clavus short, less than a third of the wing's length; A simple, arc bending and with about 4 veins.   Hind wings: length about 6.5-7.1 mm, width of remigium 2.8-3.5 mm; with intercalaries and without pterostigma; with about 22 veins of remigium; Sc simple, sometimes unclear; R terminating to wing apex, differentiated into darkened R1 with 2-3 branches and Rs with 7-9 branches; M almost straight to posterior wing margin, with 3-5 branches; CuA with about 7 branches. Legs: length of fore femora 1.16-1.49 mm and tibiae 1.16-1.22 mm, length of mid femora 1.89-1.93 mm and tibiae 1.47-1.56 mm, length of hind femora 2.12-2.19 mm and tibiae 2.59-3.45 mm; legs gradually get longer from the front to the hind legs; mid and hind leg with spines on the tibiae.
Etymology. The specific name is derived from the Latin word "peregrinus", (meaning "strange"), for this new species is special for specific characters.

Discussion
As shown in Table 1, although the total number of forewing veins of P. peregrina is stable, variability of the wing venation and difference between the left and right wings of the same individual are obvious. For example, the right forewing of holotype of P. peregrina differs from the left forewing in the following characters: (1) R with 9 branches in right forewing vs. 13 branches in left; (2) M with 7 branches in right forewing vs. 5 branches in left; (3) CuA with 8 branches in right forewing vs. 7 branches in left. We can also see the difference between the left and right wings of the paratype of P. peregrina.