Praeaulacus obtutus Li, Shih & Ren, 2014

Li, LongFeng & Shih, ChungKun, 2014, Two new fossil wasps (Insecta: Hymenoptera: Apocrita) from northeastern China, Journal of Natural History 49 (13), pp. 829-840 : 831-834

Praeaulacus obtutus Li, Shih & Ren sp. nov.

( Figures 1 , 2 )

Etymology

The specific epithet is derived from the Latin word obtutus (contemplation), indicating the posture of this wasp.

Material

Holotype CNU-HYM-NN-2012039 p/c, part and counterpart .

Locality and horizon

Jiulongshan Formation, Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia, China; Middle Jurassic.

Diagnosis

Antenna longer than mesosoma. Mesosoma short and stout; pronotum comparatively long; mesonotum not very long, combination of pronotum and mesonotum transversely ridged and nearly arched. Forewing with first abscissa of Rs (1-Rs) shorter than its distance to pterostigma; 2r-rs meeting Rs basad of 2r-m and slightly shorter than the maximal width of 2rm; 3rm shorter than 2rm, with 3r-m bending; 2rm in contact with 1mcu by a short section of M; cu-a interstitial. Hind wing with M and Cu possessing free ends; cu-a strongly oblique, meeting Cu distad of M + Cu fork. Hind legs very long.

Description

A wasp in lateral view; body and wings well preserved; forewing, hind wing and metasoma partially overlapping, but the venation mostly discernible with alcohol ( Figure 1C ).

Body 6.2 mm long; head medium-sized, 0.9 mm long and 1.2 mm high, with large eyes and irregular oval-shape; antenna, longer than mesosoma, with 16 antennomeres, as preserved and 2.5 mm long ( Figure 1A, B ); mesosoma stout, 1.9 mm long and 2.0 mm high ( Figure 1 D, E ); pronotum, mesonotum, mesoscutellum, metanotum, propodeum, mesopleuron and hind coxa are clearly discernible ( Figure 1 D, E ); the pronotum comparatively long; mesonotum not very long, the combine of pronotum and mesonotum transversely ridged and nearly arched; the mesoscutellum nearly as long and wide as metanotum; propodeum short, but broad in profile aspect; metasoma is 3.6 mm long with first segment petiole-like (0.8 mm long and 0.5 mm maximal width); propodeal foramen attached high on propodeum and much closer to metanotum than to hind coxa; hind legs very long, the lengths (in mm) of hind leg, coxa, trochanter, femur, tibia and the 1st to 5th tarsus: 0.7: 0.3: 1.4: 2.3: 0.4: 0.4: 0.2: 0.2 ( Figure 1 A ).

Forewing 3.8 mm long and 1.6 mm wide, with first abscissa of Rs (1-Rs) shorter than that of M (1-M), also shorter than its distance to pterostigma, measurements (in mm) of 1-Rs, 1-M, and the distance from 1-Rs to pterostigma about 0.2: 0.3: 0.5; vein 2r-rs arising from pterostigma about its basal one-half length, slightly shorter than the maximal width of cell 2rm and meeting Rs considerably basad of 2r-m; vein 2r-m nearly straight and 3r-m slightly bending; cell 2rm longer than 3rm, the latter wider than 2rm; cell 1mcu nearly parallelogrammic, about twice as long as wide; vein 2m-cu meeting 3rm at one-fifth of its posterior margin; cell 2mcu 1.5 times as broad as 1mcu and 1.4 times as long as 1mcu; vein cu-a interstitial and longer than 1-M, 2cu-a about half as long as cu-a.

Hind wing 1.3 mm long and 1.1 mm wide as preserved, with r-m straight and about 0.7 times as long as 1-Rs; the first section of M (1-M) nearly straight, 2.5 times as long as r-m; vein cu-a strongly oblique, meeting Cu beyond the forking of M + Cu into M and Cu; anal vein A present.

Remarks

Praeaulacus obtutus sp. nov. is assigned to Praeaulacidae based on a combination of forewing and body characters: medial mesonotal suture well developed, forewing venation with most of the main veins and metasoma attached high. It is attributed to Praeaulacinae based on several characters: antenna with more than 15 antennomeres, mesonotum transversely ridged, forewing with 2r-m, 3r-m and 2m-cu present, cu-a interstitial, and 1r-rs and 2A absent, hind wing with R strong and reaching apex of Rs. Praeaulacidae is a paraphyletic group in respect to the other Evanioidea . All the clade of Evanioidea is synapomorphic in having upper attachment of metasoma on the propodeum, which is closed below the attachment foramen. Praeaulacidae other than Nevaniinae are synapomorphic in lost 2A vein and a1-a2 crossvein, Nevaniinae is synapomorphic in having two-segmented petiole, but Praeaulacidae as a whole has no synapomorphies.

Praeaulacus obtutus sp. nov. differs from other species of Praeaulacus by the following characters: mesosoma short and stout, nearly as long as high; pronotum comparatively long; mesonotum slightly shorter than pronotum and legs very long; forewing with first abscissa of Rs (1-Rs) shorter than its distance to pterostigma, 2r-rs slightly shorter than the maximal width of 2rm.

Figures

Figure 1. Praeaulacus obtutus sp. nov., photographs of holotype CNU-HYM-NN-2012039p/c. (A) Part (CNU-HYM-NN-2012039p); (B) counterpart (CNU-HYM-NN-2012039c); (C) wings of counterpart (with alcohol); (D) head and thorax of part (with alcohol); (E) head and thorax of counterpart. pro, pronotum; me, mesonotum; mm, mesoscutellum; met, metanotum; pm, propodeum; hc, hind coxa. Scale bars = 1 mm.

Figure 2. Praeaulacus obtutus sp. nov. line drawings of holotype. (A) Body with wings (CNU- HYM-NN-2012039p); (B) body with wings (CNU-HYM-NN-2012039c); (C) forewings of counterpart; (D) hind wing of counterpart. Scale bars = 1 mm.