Epimesoplecia prosoneura, Lin, Xiuqin, Shih, Chungkun & Ren, Dong, 2015

Lin, Xiuqin, Shih, Chungkun & Ren, Dong, 2015, Revision of the genus Epimesoplecia Zhang, 2007 (Diptera, Nematocera, Protopleciidae) with five new species, ZooKeys 492, pp. 123-143 : 125-129

Taxon classification Animalia Diptera Protopleciidae

Epimesoplecia prosoneura sp. n. Figs 4, 5

Etymology.

The epithet of prosoneura is derived from the Greek preposition “pro”, meaning “before”, and Greek word “neura”, meaning "string or sinew", referring to proximal position of the fork of Rs. The specific epithet is a noun in apposition.

Diagnosis.

Compound eyes crescent. Antennae moniliform. Sc exceeding the level of r-m or very close to r-m; fork of Rs proximad of fork of M1+2; R2+3 very close to crossvein r-m; R2+3, almost straight, distinctly longer than bRs and dRs combined; bRs about 10 times (9.4-10.5) as long as dRs, the latter as long as r-m; bM1+2 shorter than dM1+2; bM3+4 shorter than m-cu; cell bp wider than cell ba terminally.

Material.

Holotype: male, NO. CNU-DIP-NN2013207p/c, part and counterpart, an almost complete specimen with well-preserved antennae, both wings and part of legs (Fig. 4A, B). Allotype (paratype): female. NO. CNU-DIP-NN2013214, in dorsal view, a specimen with well-preserved wings and body (Fig. 5A, B).

Horizon and locality.

All specimens were collected from the Jiulongshan Formation, late Middle Jurassic age (Late Callovian) from Daohugou Village, Ningcheng County, Inner Mongolia Autonomous Region in China.

Description.

Head (Figs 4C and 5C): Oviform. Compound eyes protrusive in males. Antennae long, scape and pedicel thick and stout, the 1st flagellomere slender and long, the remaining ones becoming thinner toward apex.

Thorax (Figs 4A, B and 5A): Prothorax barely visible; scutum of mesothorax broad and oval, convex obviously; scutellum of metathorax projecting, semicircle; haltere depressed.

Legs (Figs 4A, B and 5A): Forelegs relatively slender; femur slender and long, covered with dense setae, slightly shorter than tibia; tarsi not preserved. Mid legs similar to forelegs, femur long and slender, tibia thinner than femur as preserved; Hind legs: femur slightly expanded, tibia slightly longer than femur as preserved.

Wings (Figs 4H and 5B): Wing long and narrow (length: 8-8.9 mm, width: 2.6-2.7 mm), apex of wings covering the abdominal terminalia. Costal field long and thin, Sc reaching C at the middle of anterior margin; Rs arising from basal one-fourth of wing length, furcating distad to fork of M1+2; bRs about 5 times (4.8-5.7) as long as r-m; crossvein m-cu slightly longer than r-m; CuA slightly curved, ending at posterior margin distad of mid wing; vein A1 nearly straight, reaching posterior margin.

Male genitalia (Fig. 4G): Abdomen cylindrical; genitalia complex, slightly narrower than the 8th segment, with gonocoxites robust and rounded; gonostylus cylindrical and elongated, shorter than gonocoxites.

Female genitalia (Fig. 5D): The 8th segment slightly smaller than preceding segments, genitalia simple, with 2-segmented cerci, the basal segment of cerci longer than the terminal one.

Dimensions of holotype

(in mm). [Measurements for the paratype CNU-DIP-NN2013214 in brackets, if different]. Holotype: male, CNU-DIP-NN2013207p/c, Body length 9.3 [8.2], maximal width of body 1.6 [1.4]. Antennae length: 1.8 (segments 1-16) [1.4 (segments 1-15)]. Foreleg: femur 1.6 as preserved; tibia 2.5 as preserved. Mid leg: femur 1.9 as preserved; tibia 2.7 as preserved. Hind leg: femur 2.2 as preserved [2 as preserved], tibia 3.5 as preserved [1.3 as preserved]. Wing: length 8 [8.9], width 2.6 [2.7]; R2+3 3 [3.7]; bRs 1.9 [2.3]; dRs 0.1 [0.3]; R4+5 3.6 [4].

Remarks.

The new species is similar to Epimesoplecia shcherbakovi Zhang, 2007 but differs from the latter in having bRs about 10 times (9.4-10.5) as long as dRs (vs. 4.5 times); Rs bifurcation proximad of fork of M1+2 (vs. Rs bifurcation at the same level of fork of M1+2); dM1+2 longer than bM1+2 (vs. dM1+2 shorter than bM1+2); R2+3, very close to the position crossvein r-m, distinctly longer than bRs and dRs combined (vs. R2+3, distad of the position crossvein r-m, clearly shorter than bRs and dRs combined). The new species differs from Epimesoplecia plethora sp. n. in having bRs about 10 times (9.4-10.5) as long as dRs (vs. less than 2 times); bM3+4 clearly shorter than m-cu (vs. bM3+4 shorter than m-cu); Rs bifurcation proximad of fork of M1+2 (vs. Rs bifurcation distad of fork of M1+2); dRs distinctly shorter than r-m (vs. dRs about 3 times as long as r-m); R2+3, very close to the position crossvein r-m, distinctly longer than bRs and dRs combined (vs. R2+3, sigmoidly curved, distinctly shorter than bRs and dRs combined). Comparisons with other species are listed in Table 1.