Epimesoplecia macrostrena, 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 : 129-131

Taxon classification Animalia Diptera Protopleciidae

Epimesoplecia macrostrena sp. n. Figs 7, 8

Etymology.

The epithet of macrostrena is derived from the Greek prefix “macro-”, meaning “large”, and Greek word “strenos”, meaning "insolence or excess of strength", referring to the large wings and strong body of this species. The specific epithet is a noun in apposition.

Diagnosis.

Antennae filiform. Sc very close to the level of r-m; fork of Rs proximad of fork of M1+2; R2+3 distad of crossvein r-m; R2+3, straight, slightly shorter than bRs and dRs combined; bRs about 5 times (4.2-5) as long as dRs, the latter almost equal to r-m; bM1+2 shorter than dM1+2 (0.7 times); bM3+4 shorter than m-cu (barely longer than m-cu); cell bp slightly wider than cell ba terminally.

Materials.

Holotype: sex unknown. NO. CNU-DIP-NN-2013211, in lateral view, a well-preserved specimen with partial antennae, wings and body as preserved (Fig. 7). Paratypes: CNU-DIP-NN-2013206p/c, sex unknown, a well-preserved specimen with almost complete wings and body (Fig. 8A, B), NO. CNU-DIP-NN-2013212, female, in ventral view, a well-preserved specimen with complete wings and body as preserved (Fig. 8E).

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 7C, D and 8C): Oviform and very small in lateral view; antennae filiform, segments 1-9 well-preserved, scape and pedicel slightly compressed; flagellar segments slender and long, becoming thinner and shorter toward apex (moniliform in CNU-DIP-NN-2013206p/c in Fig. 8C); maxillary palpi segments not visible.

Thorax (Figs 7A, B and 8E): Scutum well-developed, arched convex; scutellum depressed; haltere clearly depressed.

Legs (Figs 7A, B and 8E): Forelegs: femur thicker than tibia; almost four-fifths of tibia; the 1st tarsomere longer than half of tibia, the 2 nd– 5th greatly thinned than the former. Mid legs: femur slightly thicker than tibia; tibial spurs minute; the 1st tarsomere slightly longer than the 1st tarsomere of forelegs. Hind legs: femur expanded almost equal to tibia; tibial spurs minute; tarsi not preserved.

Wings (Figs 7E, 8D and F): Wing long and narrow (length: 7.1-8 mm, width: 2.3-3.2 mm), apex of wings not reaching the abdominal terminalia. Costal field long and thin, apex of Sc gradually tapering to the end; Rs arising almost from basal one- fifth of wing length, furcating proximad of fork of M1+2 bRs 4.4-5.6 times as long as r-m; crossvein m-cu slightly shorter than r-m; CuA arched near anal margin; vein A1 nearly straight, reaching posterior margin.

Female genitalia (Fig. 8F): In lateral view, genitalia simple, with 2-segmented cerci.

Dimensions

(in mm). [Measurements for the holotype in brackets]. Body length 7 (as preserved)-11.3 [10.3 as preserved]; antennae 0.9 (as preserved)-1.4 (segments 1-16) [0.9 segments 1-9]. Forelegs: femur 2.1-2.5 [1.8 as preserved]; tibia 2.9-3.1 [2.7 as preserved]. Mid leg: femur 2.4-3.8 as preserved [3.8 as preserved]; tibia 2.7-3.6 as preserved [3.6 as preserved]. Hind leg: femur 3.4-4.7 [4.7], tibia 3.8-4.8 [4.8]. Wing: length 7.1-8 [7.4 as preserved], width 2.3-3.3 [3.3]; R2+3 2.4-3.2 [3.2]; bRs 1.9-2.9 [2.9]; dRs 0.5-0.8 [0.6]; R4+5 3-3.7 [3.7].

Remarks.

The new species is similar to Epimesoplecia shcherbakovi Zhang, 2007, but is differentiated from the latter by having Rs bifurcation proximad of fork of M1+2 (vs. Rs bifurcation at the same level of fork of M1+2); bM1+2 shorter than dM1+2 (vs. bM1+2 longer than dM1+2); dRs as long as r-m (vs. dRs clearly shorter than r-m); dM1+2 long, almost one-third of M2 (vs. dM1+2 short, significantly less than one-third of M2). Comparisons with other species are listed in Table 1.