Yunbayin rossei, Brazidec & Legendre & Perrichot, 2023

Brazidec, Manuel, Legendre, Frederic & Perrichot, Vincent, 2023, Diversity and phylogeny of the extinct wasp subfamily Lancepyrinae (Hymenoptera, Bethylidae) revealed by mid-Cretaceous Burmese amber, Arthropod Systematics & amp; Phylogeny 81, pp. 345-369 : 345

Yunbayin rossei sp. nov.

Figs 7 , 8

Etymology.

The specific epithet is a patronym honouring Simon Rosse-Guillevic, a former student and the senior author’s fellow from the palaeontology program at the University of Rennes. The specific epithet is to be treated as a noun in the genitive case.

Material studied.

Holotype IGR.BU-062, a complete female; paratype IGR.BU-063, a complete female; both housed in the Geology Department and Museum of the University of Rennes, France (IGR).

Type locality and horizon.

Holotype from Hkamti site, Hkamti district, Sagaing Region, Myanmar; early Albian, ca. 110 Ma, Early Cretaceous. Paratype from Noije Bum, Hukawng Valley, Kachin State, northern Myanmar; late Albian-early Cenomanian, ca. 99 Ma, mid-Cretaceous.

Diagnosis.

As for genus

Description.

Body weakly depressed, elongate, poorly pubescent (length 2.43 mm). - Head prognathous, subquadrate and longer than high; LH: 0.42 mm, WH: 0.37 mm, WF: 0.25 mm, HE: 0.21 mm, VOL: 0.12 mm; frons flat; compound eye elliptical, longer than high, not covering head length, located on anterior half of head, closer to mandible than to occipital carina; antenna filiform, shorter than head + mesosoma combined; scape 2.8 times as long as pedicel (length 0.11 mm); pedicel longer than flagellomeres 1-10, thicker (length 0.04 mm); flagellomeres elongate, longer than wide; flagellomeres 1-10 gradually thickening, flagellomere 10 almost as long as wide (length 0.03 mm); flagellomere 11 longest (length 0.06 mm), tapering at apex; at least four maxillary palpomeres; occipital carina present. - Mesosoma flattened, with dorsum smooth (length 0.76 mm; height 0.21 mm); propleuron elongate and visible in dorsal view; prosternum short between procoxae; dorsal pronotal area narrower than anteromesoscutum, with lateral margin incurved, posterior margin slightly concave; anteromesoscutum shorter than dorsal pronotal area, with notaulus present and convergent posteriorly, parapsidal signum present; scutellum posteriorly overlapped by metanotum; metapectal-propodeal complex carinate, rectangular, without posterior spine. Fore wing hyaline, reaching at least third metasomal segment (LFW: 1.39 mm); C, Sc+R, M+Cu, 1A tubular; 1Rs&1M only slightly angled at junction with Rs+M; 1Rs shorter than 1M; cu-a slightly post-furcal to 1M; Rs+M tubular, reaching apex of pterostigma; pterostigma slightly rounded and elongate; short stub of post-stigmal abscissa of R1 present; 2r-rs&Rs arising on distal half of pterostigma, long but not closing [2R1] cell; [2R1] cell narrow, lanceolate. Hind wing without apparent venation; at least three hamuli. Proleg with protrochanter originating from apex of procoxa; femora slightly enlarged; tibial spur formula 1-2-2; tarsal claws only slightly curved; arolium present, as long as claws. - Metasoma cylindrical, not flattened (length 1.25 mm; height 0.39 mm); petiole long and conspicuous; seven visible segments; metasomal tergites decreasing in length; ovipositor not exserted. - Paratype. Similar to holotype but longer. Body length 2.92 mm; LH: 0.56 mm; fore wing with Rs+M hardly distinguishable distally but clearly tubular, reaching apex of pterostigma (LFW: 1.46 mm); proleg with internal musculature exquisitely preserved; mesosoma length 1.08 mm, height 0.27 mm; metasoma length 1.28 mm, height 0.31 mm; ovipositor exserted, long (length 0.34 mm).

Remark.

Although the two specimens of the type series originate from deposits considered distinct in age, they do not show much variation. Therefore, we assign them to the same species, pending further material. To our knowledge, it is the first instance of a shared species between Hkamti and Noije Bum (Kachin) amber.

Figures

Figure 7. Yunbayin rossei gen. et sp. nov., holotype female IGR. BU- 062. A habitus in lateral view; B head and mesosoma in dorsal view; C fore wing in dorsal view; D line drawing of fore wing; paratype IGR. BU- 063; E habitus in lateral view; F head and mesosoma in lateral view. Scale bars: 1 mm (A, E); 0.5 mm (B, C, D, F).

Figure 8. Line drawings of Yunbayin rossei gen. et sp. nov., holotype female IGR. BU- 062. A habitus in lateral view; B head and mesosoma in dorsal view. Scale bar: 1 mm.