Similsciophila singularis, Shi & Shih & Ren, 2014

Shi, GuiFeng, Shih, ChungKun & Ren, Dong, 2014, A new genus with two new species of mesosciophilids from the Middle Jurassic of China (Diptera: Nematocera: Mesosciophilidae), Journal of Natural History 49 (19), pp. 1147-1158 : 1150-1154

Similsciophila singularis sp. nov.

( Figures 1A–D , 2A–F , 3A, B )

Diagnosis

Wing membranous, 2.2–2.4 times as long as wide; R 2+3 slightly curved, almost perpendicular to R 4+5; bRs long and 1.1–1.4 times as long as r-m; dM 1+2 about 1.4–1.8 times as long as bM 1+2; bM 1+2 about 2.0–2.4 times as long as m-cu.

Material

Holotype No. CNU-DIP-NN2011226 , a well-preserved complete body with a haltere and two wings . Paratype No. CNU-DIP-NN2011147 p/c, a specimen in lateral aspects with part of wings overlapping.

Etymology

The specific name is from the Latin ( singularis ), meaning single, for all the veins are single.

Locality and horizon

Late Middle Jurassic, Jiulongshan Formation, Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia, China ( Ren et al. 2010).

Description

Medium-sized mesosciophilid gnats, male adult, in dorsal aspects. Wings out-spread. Head poorly preserved. Antennae 19 segments (as preserved on Paratype), with all flagellomeres oblong and nearly the same size in length and width. Body covered with long dense pubescence. Mesonotum convex, scutellum clearly projecting. Abdomen thin, subcylindrical, about 2.7 times as long as head and thorax combined, with eight abdominal segments, first five segments gradually widened distally, sixth, seventh and eighth gradually narrowed terminally. Male genitalia relatively small, distinctly narrower than eighth abdominal segment. Haltere well-preserved, spatulate, and with its inner margin straight. Legs relatively thin and long, coxae and femora clavate; femora, tibiae and tarsi with two rows of sparse and short setae.

Wing membranous, oblong, darker in colour in costal area, 2.4 times as long as wide, and not reaching apex of abdomen at rest. C strong, ending beyond wing apex, at which R 4+5 ending. Sc long, about 0.4 times as long as wing (shorter than one-half of wing length), and ending far distal to crossing of bRs and r-m. h distinct, and curved. sc-r well developed, situated distinctly basal to Rs origin, arising near midway between h to Sc ending at margin. Cell r distinctly large, longer than one-sixth of wing length (about 0.2 times as long as wing length). The section of R from sc-r to Rs origin about 1.8 times as long as bRs. R furcated to three branches (R 1, R 2+3 and R 4+5). Both R 1 and R 4+5 running somewhat divergent terminally. R 2+3 and R 4+5 arched. Forking of Rs beyond level of forking of M. Rs usually strongly furcated, arising from less than basal one-third of length of wing, with nearly 0.4 times as long as R 4+5, basal near to midwing to R 2+3 and R 4+5, but furcated distad to fork of M 1+2. bRs significantly long, and 1.3 times as long as r-m. R 1 slightly curved, relatively long (nearly 0.7 times of length of wing). R 2+3 slightly curved, beyond level of M 1+2 forking, almost perpendicular to R 4+5. R 4+5 strongly arched near its midway. Stem of M not developed, thin, usually thinner than its branches, and furcated to M 1, M 2 and M 3+4. M 1 arched upwards, and subparallel to R 4+5. M 2 nearly straight. r-m short, slightly oblique, nearly upright with M 1+2, almost parallel to R 2+3, intersected at M 1+2, which furcated to bM 1+2 and dM 1+2. dM 1+2 about 1.7 times as long as bM 1+2, and longer than r-m. bM 1+2 about 2.3 times as long as m-cu. CuA running close to M 3+4 basally, but neither coalescent. Vein A short, slightly curved at its midway, ending far from posterior margin of wing.

Dimensions (mm)

CNU-DIP-NN2011226 (male, Holotype): Body length 6.2 (excluding head, antenna length 0.9, width 0.1; thorax length 1.6, width 1.3; abdomen length 4.6, width 1.6); wing length 4.7, width 2.0; hind leg length 4.4 (femur length 0.9, tibia length 2.2, tarsus length 1.3).

CNU-DIP-NN2011147 (male, Paratype): Body length 5.5 (antenna length 1.5, width 0.1; head length 0.4, width 0.7; thorax length 1.5, width 1.3; abdomen length 3.6, width 1.1); wing length 2.6 (missing basal part), width 1.4; hind leg length 3.5 (femur length 0.8, tibia length 1.2, tarsus length 1.5).

Figures

Figure 1. Similsciophila singularis gen. et sp. nov., holotype, CNU-DIP-NN2011226. (A) Photograph of habitus (dorsal aspect); (B) photograph of wing part; (C) line drawing of habitus; (D) line drawing of wing venation.

Figure 2. Similsciophila singularis gen. et sp. nov., paratype, CNU-DIP-NN2011147 p/c. (A) Photograph of habitus (lateral aspect), part; (B) photograph of counterpart; (C) line drawing of holotype, counterpart; (D) photograph of antennae; (E) photograph of antennae with alcohol; (F) line drawing of antennae.

Figure 3. Similsciophila singularis gen. et sp. nov., paratype, CNU-DIP-NN2011147 p/c. (A) Photograph of wing part; (B) line drawing of wing part.