Prosyntexis aristovi Li, Shih & T. Gao, 2023

LI, XIAO-QIN, RASNITSYN, ALEXANDR P., GAO, JIA, ZHANG, YAN-JIE, SHIH, CHUNG-KUN, REN, DONG, ZHAO, YUN-YUN & GAO, TAI-PING, 2023, New taxa of Sepulcidae (Hymenoptera) from mid-Cretaceous Kachin amber, Palaeoentomology 6 (2), pp. 133-145 : 134

Prosyntexis aristovi Li, Shih & T. Gao sp. nov.

( Figs 1 , 2 )

Type material. Holotype: CNU-HYM-MA2015105, male specimen. Most of body preserved, but major parts of head and mesonotum obscured by inclusions in ventral view. Left forewing and left and right hind wings folded over abdomen obscuring abdomen dorsally.

Etymology. The specific name “ aristovi ” is dedicated to the memory of the late Dr Daniil Sergeevich Aristov, for his outstanding contribution to palaeoentomological research.

Diagnosis. The new species is unique within Prosyntexis in having 2+3A widely interrupted before the cu-a crossvein. It also differs from other species in having a short and thin crossvein-like Sc in the forewing.

Locality and horizon. Hukawng Valley, Kachin State, northern Myanmar; lowermost Cenomanian, mid-Cretaceous.

Description. Body about 4.91 mm long, antenna 7.86 mm long in dorsal view; forewing about 4.66 mm in length, maximum width 2.08 mm ( Fig 1A, B ).

Head nearly 0.93 mm wide and 0.67 mm long, rather large and subquadrate. Compound eyes rather small and oval. In ventral view, maxillary palpus with at least five palpomeres; labial palpus indiscernible. Antenna elongate and filiform with 16 segments; scape 0.22 mm long, maximum width 0.14 mm, slightly swollen apically; pedicel 0.40 mm long, maximum width 0.10 mm, slightly swollen apically and thinner than scape; flagellomere I longer than scape and pedicel 0.77 mm long, 0.10 mm wide; flagellomere II 0.76 mm long, 0.09 mm wide, as wide as individual widths of remaining flagellomeres ( Fig. 2B ).

Thorax only partially visible with a deep medial membranous depression in the mesonotum bordered laterally by strong striate surfaces ( Fig. 2C ). Legs spindly, meso- and metafemur thicker than associated tibiae; metafemur length 0.95 mm, metatibia 1.50 mm long, maximum width 0.07 mm. Protibia with one apical spur ( Fig. 2E ), mesotibia with two apical spurs ( Fig. 2F ), metatibia with two apical spurs (the smaller spur thick, less than half length of larger spur) ( Fig. 2G ); basitarsomere long but shorter than remaining tarsomeres combined; tarsomere V not elongate; pretarsal claws short, with curved apices and additional inner teeth ( Fig. 2D ).

Forewing ( Fig. 1C ) with C strongly thickened; R greatly thickened before base of Rs; basal third of costal space narrowed; crossvein-like Sc short and thin, appearing just before origin of Rs; 1-Rs slanted toward wing apex and 1.4× as long as 1-M; pterostigma broad, oblong and 3× as long as wide with center slightly translucent; 1-M+Cu bent basally; 2-M+Cu exceptionally short, nearly 0.05 mm long, scarcely present owing to the proximal position of cu-a near the origin of 1-Cu. 2- Rs+M short and 1/5× as long as 1-Rs+M; end of 2-Rs weakened; 1r-rs connected to pterostigma at its base and nearly as long as section of Rs between 1r-rs and 2r-rs; 2r-rs issuing from 1/4 of pterostigma and at 1/3 of 2+3rm length; 2rs-m absent; 3-M slightly shorter than 3rs-m. Cell 1mcu subquadrate, about 2× as long as wide; cell 2mcu hexagonal, about 1.5× as long as wide. 2+3A widely interrupted before 1a-2a. Hind wing with cell r closed, other parts indiscernible. Abdomen visible only ventrally, with hypopygium triangular with widely rounded apex; male genitalia not exerted, with only narrow gonocoxa partly visible.

Figures

FIGURE 1. One photograph and two line drawings of Prosyntexis aristovi sp. nov., holotype (specimen CNU-HYM-MA2015105) male. A, Habitus in dorsal view. B, Line drawing in dorsal view. C, Line drawing of the right forewing. Scale bars: 1.0 mm for A and B; 0.5 mm for C.

FIGURE 2. Photographs of Prosyntexis aristovi sp. nov., holotype (specimen CNU-HYM-MA2015105) male. A, Photograph of habitus in ventral view. B, Part of antenna. C, Mesonotum, with arrows indicating transverse ridges. D, Right mesotarsal pretarsal claw. E, Left protibial spur. F, Right mesotibial spurs. G, Left metatibial spurs. Abbreviations: Fla1 and Fla2, flagellomeres I and II; Pe, pedicel; Sc, scape. Scale bars: 1.0 mm for A, D, E–G; 0.5 mm for B; 0.2 mm for C.