Megacoxa janzeni, Brazidec & Vilhelmsen & Boudinot & Richter & Hammel & Perkovsky & Fan & Wang & Wu & Wang & Perrichot, 2024

Brazidec, Manuel, Vilhelmsen, Lars, Boudinot, Brendon E., Richter, Adrian, Hammel, Joerg U., Perkovsky, Evgeny E., Fan, Yong, Wang, Zhen, Wu, Qiong, Wang, Bo & Perrichot, Vincent, 2024, Unveiling ancient diversity of long-tailed wasps (Hymenoptera: Megalyridae): new taxa from Cretaceous Kachin and Taimyr ambers and their phylogenetic affinities, Arthropod Systematics & amp; Phylogeny 82, pp. 151-181 : 151

3.1.1.3.2. † Megacoxa janzeni sp. nov.

Figures 2E and 7

Etymology.

The specific epithet is a patronym honoring Jens-Wilhelm Janzen, former owner of the holotype specimen.

Material studied.

Holotype female IGR.BU-069; housed in the amber collection of the Geology Department and Museum of the University of Rennes , France (IGR). One paratype male NIGP203547; housed in the Nanjing Institute of Geology and Paleontology (NIGP), Chinese Academy of Sciences, Nanjing, China.

Type locality.

Noije Bum Hill, Hukawng Valley, Kachin State, Myanmar.

Age.

Upper Albian to lower Cenomanian, mid-Cretaceous.

Diagnosis.

Median mesoscutal sulcus smooth (vs. crenulate in Megacoxa synchrotron gen. et sp. nov.); axillae not contiguous medially (vs. contiguous in † Megacoxa chandrahrasa gen. et sp. nov. and Megacoxa synchrotron gen. et sp. nov.); fore wing with very narrow marginal cell closed in straight line by Rs (vs. broad with Rs curved in † Megacoxa chandrahrasa gen. et sp. nov.); trapezoid medial cell (Fig. 2E ; vs. narrow in † Megacoxa chandrahrasa gen. et sp. nov.); posterior margin of metacoxa outcurved and bordered with large foveae (Fig. 7B ; vs. bordered with small foveae in † Megacoxa chandrahrasa gen. et sp. nov. and and straight posterior metacoxal margin in Megacoxa synchrotron gen. et sp. nov.).

Description.

Body length for holotype 5.20 mm; for paratype 3.72 mm. - Head glabrous, globular, higher than long (length for holotype 0.81 mm; for paratype 0.69 mm; height for holotype 1.04 mm; for paratype 0.75 mm); compound eye oval, higher than long, ocular carina absent; vertex convex, shagreened; clypeus short; subantennal groove present; antenna short, less than half as long as body; scape as long as wide (length for holotype 0.19 mm); pedicel wider than long (length for holotype 0.12 mm); flagellomeres cylindrical, elongate; mandibles symmetrical, with three teeth; occipital carina minutely crenulate. - Mesosoma half as long as body length (length for holotype 2.28 mm; for paratype 1.62 mm); mesoscutum one third as long as mesosoma (length for holotype 0.92 mm; for paratype 0.63 mm; width for holotype 1.03 mm), shagreened, overhanging pronotum almost at right angle, divided by smooth median mesoscutal sulcus; parapsidal line present; axillae not contiguous medially, inner axillar groove crenulate; pronotum with posteromedial part moderately high as viewed laterally; anterior thoracic spiracle not fully surrounded by pronotal cuticle; mesometapectal sulcus crenulate; propodeum carinate. - Fore wing hyaline and covered with microtrichiae, about two thirds of body length (length for holotype 3.08 mm; for paratype 2.58 mm); R1, Sc+R and M+Cu pigmented, Rs present between r-rs and Rs+M, composing first submarginal cell, M and A pigmented, Rs closing in a straight line a very narrow medial cell, trapezoid medial cell composed by basal segments of M, Rs+M and Cu1 (shortest side) and by 1m-Cu, Cu pigmented to margin with a bend. - Legs with metacoxa enlarged, posteriorly curved, and notched just before trochanter insertion, bearing a row of large foveae along posterior margin; two mesotibial spurs present; metafemur swollen and bare; metatibia also swollen, with two spurs and bearing row of comb-like setae that continue on metabasitarsus; metatarsus almost as long as metatibia; metabasitarsus four times longer than following metatarsomeres. - Metasoma shorter than mesosoma, covered with short setae (length for holotype 2.12 mm; for paratype 1.41 mm); first tergite longest and second almost same length; third, fourth and fifth of similar length and shorter than first; last tergite twice as long as fifth; tergite and sternite inserted in bevel; hypopygium well-developed; ovipositor same length as metasoma (length for holotype 2.10 mm; OL/BL ratio 0.40), sheaths fully preserved in holotype, transversely striated.

Figures

Figure 2. Drawings of fore wing venation for the taxa described in the present paper. A † Cretolyra noijebumensis gen. et sp. nov.; B † Cretolyra shawi gen. et sp. nov.; C † Genkyhag innebula gen. et sp. nov.; D † Megacoxa chandrahrasa gen. et sp. nov.; E † Megacoxa janzeni gen. et sp. nov.; F † Megacoxa synchrotron gen. et sp. nov.; G † Kamyristi exfrigore gen. et sp. nov.; H † Kamyristi yantardakhensis gen. et sp. nov. Scale bars: 0.5 mm (A - H).

Figure 7. † Megacoxa janzeni gen. et sp. nov., mid-Cretaceous, Kachin amber; A holotype female IGR. BU- 069, habitus in lateral view; B mesosoma in lateral view; C head in frontal view; D paratype male NIGP 203547, habitus in lateral view; E head and mesosoma in lateral view (scale bars: A, D = 2 mm; E = 1 mm; B, C = 0.5 mm). Abbreviations: Cx = hind coxa; MeS = mesometapectal sulcus; PpL = parapsidal line; sp = anterior thoracic spiracle.