Hemisyntexis lepida Li, Wang, Rasnitsyn & Shih, 2024

Hemisyntexis lepida Li, Wang, Rasnitsyn & Shih , sp. nov.

urn:lsid:zoobank.org:act:CE39453F-60D6-4BDD-9850-3B70BC411AD2

Material. Only the holotype, CNU-HYM-LB2024501 .

Etymology. The specific name is from Latin “lepidus”, meaning exceptional and referring to the well-preserved fossil specimen.

Horizon and locality. Huangbanjigou, Chaomidian Village, Shangyuan Township, Beipiao City, Liaoning Province, China; Lower Cretaceous (Barremiane–Aptian), Yixian Formation.

Diagnosis. As for the genus.

Description. Female. Head entirely dark, slightly darker than thorax and abdomen, with ovipositor slightly darker; legs lightly colored; wing veins dark ( Fig. 1 View FIGURE 1 ).

Head: Moderately large, narrower than thorax, nearly round shaped. Eye elongate ovoid, occupying all head side; ocelli small, in wide triangle at level before eye midlength ( Fig. 1A View FIGURE 1 ). Antenna thin, with almost uniform width, flagellomeres partly preserved and almost equal in lengths, maximum 0.39 mm in length and 0.25 mm in width ( Fig. 1E View FIGURE 1 ).

Thorax: Pronotum short and trapezoid, at least four times as wide as long; pronotum posterior border slightly curved in dorsal view. Mesoscutum large, with anterior margin nearly straight, with longitudinal sulcus and notauli strongly impressed ( Fig. 1B View FIGURE 1 ); mesoscutellum tapering to acutely sharp apex; ratio of lengths of prescutum, longitudinal sulcus between notauli and scuto-scutellar sulcus and scutellum 3.3/2.1/4.0. Mesopostnotum trapezoid ( Fig. 1C View FIGURE 1 ), slightly narrower than metascutellum; metascutum with metascutellum small, rounded quadrangularly, transverse; cenchri present and small.

Leg: Legs spindly. Tarsi pentamerous, basitarsi long but shorter than remaining tarsomeres combined; tarsomeres ( Fig. 1D View FIGURE 1 ) about twice as long as wide; pretarsal claws more than half length of fifth tarsomere, with curved apices.

Wing: Forewing three times as long as wide ( Fig. 1G View FIGURE 1 ); vein C and R slightly bent, 1r-rs 1.2 times as long as 2r-rs; 1-Rs long and proclival, about twice as long as 1-M; 2-M distinct, 0.2 times as long as Rs+M; M+Cu slightly bent basally; 3+4-M 2.4 times as long as 5-M; 5-M 1.2 times as long as 3r-m; 3r-m and 2m-cu vertical; 2-Cu twice as long as 1-Cu; 1cu-a straight, lying basally of cell a, as long as 1-Cu; 2+3A with distinct subbasal loop; cell 2+3rm long and pentagonal, about 3.4 times as long as wide. Cell 1r about 2.1 times as long as wide; cell 2r short, as long as wide; cell 3r 3.4 times as long as wide; cell 1mcu about 1.7 times as long as wide.

Abdomen: Abdomen only slightly narrower than mesothorax, first abdominal tergite split medially ( Figs. 1A, E View FIGURE 1 ). Ovipositor straight, prominent significantly behind abdomen, incompletely preserved ( Fig. 1E View FIGURE 1 ). First valvifer small, subhemicircular as visible ( Fig. 1F View FIGURE 1 ); second valvifer large narrowing up to single thickening before meeting with valvula 3 (saw sheath), six times as long as the first valvifer; valvula 2 (dorsal stylet) visible only basally at its thickened base; ovipositor sheaths almost straight, prominent significantly behind abdomen.

Measurements (in mm). Body length at least 19.21, excluding ovipositor 16.90; head length 2.54, width 2.71; antenna 4.50 long as preserved; thorax length 4.06; abdomen length 10.51; forewing 10.24 long as preserved, maximum width 2.69; ovipositor length 8.94 as preserved.