Juraserphus modicus, Zheng & Chen, 2017

Zheng, Yan & Chen, Jun, 2017, A new mesoserphid wasp from the Middle Jurassic of northeastern China (Hymenoptera, Proctotrupoidea), European Journal of Taxonomy 379, pp. 1-8 : 3-6

Juraserphus modicus gen. et sp. nov.

urn:lsid:zoobank.org:act:34160863-3F15-422F-81B7-70971337541C

Figs 1–2

Diagnosis

As for genus.

Etymology

The specific epithet is an adjective derived from the Latin word ‘modicus’, which means ‘moderate, average’, indicating that both the body and forewing lengths are medium.

Material examined

Holotype

CHINA: part and counterpart, female in dorsal view ( TYNM-48-1244 a–b ).

Locality and age

CHINA: Daohugou Village , Ningcheng County, Inner Mongolia; Callovian (latest Middle Jurassic), Jiulongshan Formation.

Description

Body length 8.66 mm. Head transversely ovoid, length 1.31 mm and width 0.63 mm. Eye large, oviod and protruding. Antenna filiform, thin, with nine antennomeres preserved, the first flagellomere long, subsequent flagellomeres gradually decreasing in length from base to apex.

Mesosoma about as wide as head; pronotum trapezoid, extremely short and obviously narrower than head and about 3.6 times as wide as long (length 0.96 mm; width 0.27 mm); mesoscutum subquadrate, 0.86 mm long and 0.37 mm wide; mesoprescutum length 0.52 mm and width 0.43 mm; notauli present and reaching transverse mesonotal suture; mesoscutellum triangular; mesopostnotum rectangular, 0.5 times as wide as long; metascutellum preserved and almost as long as wide. Metasoma spindle-shaped, with seven segments, first observed segment very short, subtrapezoidal; second to fifth segments similar to first in shape and length, but gradually increasing in width; sixth segment reversely trapezoidal and about twice as long as fourth segment; seventh segment about as long as sixth segment; valvifer 1, valvifer 2 and valvula 3 clearly discernible; ovipositor short, slightly stretched out of metasomal apex.

Left foreleg with only femur preserved, small. Left midleg well preserved, with femur wider than tibia; tibia slender; tarsus thin, with basitarsus longest and about twice as long as 2nd tarsomere, 3rd tarsomere obviously shorter than 2nd, 4th shorter and thinner than 3rd, 5th twice as long as 4th and possessing two short claws. Left hindleg with femur narrow basally and widened apically, with a spindle-like shape; tibia thicker than midtibia; tarsi similar to midtarsi.

Forewing length 7.05 mm, width 2.73 mm. Pterostigma long and slightly oblique apicad, six times as long as wide. 1-Rs and 1-M equal in length; 1-M more than twice as long as 1m-cu; 2r-rs arising from middle of pterostigma, oblique, about 2.5 times as long as pterostigmal width. Cell 1+2r five-sided and surrounded by R, 1-Rs, 1-Rs+M, (2-Rs+M) + (2-Rs) and 2r-rs; M+Cu straight and distinct, M and Cu straight basally, slightly curved apically; 1-Rs origin at a distance from pterostigma (about twice as long as 1-Rs), and 2r-rs arising from middle of pterostigma; forking of Rs+M located approximately onethird of distance between 1m-cu and 2r-rs; both 1cu-a and 2cu-a antefurcal; cell 1mcu subtrapezoidal, 1.8 times as long as wide basally; 1cu-a slightly longer than 1-M and two-thirds of 2cu-a in length. Hindwing with long, oblique r-m meeting Rs near its base; cell r long and closed; M+Cu and Cu partly tubular; M tubular.

Discussion

Various morphological characters of Mesoserphidae have been recorded from the latest Middle Jurassic to Early Cretaceous ( Zhang & Zhang 2000; Shih et al. 2011; Shi et al. 2013; Li et al. 2016). Compared with other mesoserphids, Juraserphus gen. nov. has the rare combination of both 1cu-a and 2cu-a being antefurcal in the forewing, and cells rm and r closed in the hindwing.Additionally, Juraserphus gen. nov. is unique among Mesoserphidae in having a female metasoma with five basal terga very short and jointly occupying only half of metosoma’s length, whilst the other half is formed by terga 6 and 7 only.

Juraserphus gen. nov. resembles Beipiaoserphus Zhang & Zhang, 2000 and Basiserphus Li et al., 2016 with both 1cu-a antefurcal and 2cu-a antefurcal in the forewing, but differs from them in having the forking of Rs+M located at a distance of one-third between 1m-cu and 2r-rs, and 1-M about twice as long as 1m-cu (vs one half and 1-M much shorter than 1m-cu in Beipiaoserphus ; one-sixth or onequarter and 1-M slightly longer than 1m-cu in Basiserphus ). Juraserphus gen. nov has long crossvein 2r-rs, which is more than twice as long as the width of the pterostigma. The length of 2r-rs, however, is less than 1.5 times the width of the pterostigma in Codoserphus Shi et al., 2013 and more than five times as long as the width of the pterostigma in Turgoserphus Rasnitsyn, 1990 ( Rasnitsyn 1990; Shi et al. 2013). 1cu-a and 2cu-a of the forewing offer significant characteristics. Juraserphus gen. nov has both 1cu-a and 2cu-a antefurcal, as in Campturoserphus Rasnitsyn, 1986 , Scoliuroserphus Rasnitsyn, 1986 and Basiserphus Li et al., 2016 , but is different from the latter two and from Lordoserphus Rasnitsyn, 1994 and Sinoserphus Shih et al., 2011 in the 1cu-a and 2cu-a being interstitial, from Apiciserphus Li et al., 2016 in 1cu-a and 2cu-a postfurcal, and from Amboserphus Li et al., 2016 and Yanliaoserphus Shih et al., 2011 in 1cu-a postfurcal and 2cu-a antefurcal ( Li et al. 2016). Furthermore, the position of the Rs+M forking in the forewing could be taken as a key feature. The forking of Rs+M is located one-third of the distance between 1m-cu and 2r-rs in Juraserphus gen. nov, whereas it is about one-fifth of this distance in Mesoserphus Kozlov, 1968 , Sinoserphus Shih et al., 2011 and Basiserphus Li et al., 2016 , and approximately one half in Amboserphus Li et al., 2016 and Beipiaoserphus Zhang & Zhang, 2000 .

The ovipositor of Mesoserphidae demonstrates significant variations, especially in its length, among the fossils described. The ovipositor in Juraserphus gen. nov. is similar to the one in Novserphus Li et al., 2016 and Ozososerphus Li et al., 2016 in being short, extending beyond the metasomal apex. In contrast, the ovipositor in some other genera (for example, Apiciserphus Li et al., 2016 , Amboserphus Li et al., 2016 , Udaserphus Rasnitsyn, 1983 and Choriserphus Li et al., 2016 ) does not extend beyond the metasomal apex. On the other hand, Sinoserphus Shih, Feng & Ren, 2011 (especially S. grossus Shih, Feng & Ren, 2011 ; S. flexilis Shih, Feng & Ren, 2011 and S. wui Shih, Feng & Ren, 2011 ) has a much longer ovipositor, albeit not exceeding half of the metasomal length. Furthermore, the ovipositor in Mesoserphus Kozlov, 1968 is longer than the metasoma.

Figures

Fig. 1. Holotype of Juraserphus modicus gen. et sp. nov. A. Part. B. Counterpart. C. Left forewing and left hind wing of part. D. Head and mesosoma of part (in ethanol). E. Metasoma of part. Scale bars = 2 mm.

Fig. 2. Line drawings of Juraserphus modicus gen. et sp. nov. A. Habitus. B. Left forewing. C. Left hind wing. Abbreviations: N 1 = pronotum; N 2 = mesonotum; N 3 = metanotum; nv = notaulus; tms = transverse mesonotal suture; Sc = mesoscutellum; Pr = propodeum; Vf 1 = valvifer 1; Vf 2 = valvifer 2; Vf 3 = valvula 3. Scale bar = 2 mm.