Cretaxenomerus brevis Ulmer & Krogmann, 2023

UImer, Jonah M., Jansta, Petr, Azar, Dany & Krogmann, Lars, 2023, At the dawn of megadiversity - Protoitidae, a new family of Chalcidoidea (Hymenoptera) from Lower Cretaceous Lebanese amber, Journal of Hymenoptera Research 96, pp. 879-924 : 879

Cretaxenomerus brevis Ulmer & Krogmann sp. nov.

Fig. 10

Diagnosis.

Female. Cretaxenomerus brevis differs from all other species in the genus by the following combination of characters: scape laterally flattened, only 2.25 × as long as broad; antenna with at least fu1-fu4 conspicuously longer than broad, fl1 about 3.75 × as long as broad. Anterolateral margin of mesoscutum flanged. Arolium elongated and extending beyond tip of tarsal claws. Syntergum relatively short, extending about ⅓ length of ovipositor sheath.

Description.

Female. Body length 1145. Uniformly dark brown, legs light brown, eyes white (likely an artifact of amber deposition) (Fig. 10A ). Head. Ovular in shape, wider than long, length 201, width 313. Eye almost circular. Ocelli large, equilateral, POL=LOL=OOL. Temples relatively short, at most about 0.2 × as long as eye length. Gena large, about 0.5 × as long as eye length; no genal carina or sulcus present. Toruli closer to inner margin of eye than each other and very close to dorsal margin of clypeus, well below center of eye, hence lower face short (Fig. 10C ). Clypeus dorsally with raised rim, inwardly inflexed; lower clypeal margin wide. Anterior tentorial pits situated well below dorsal margin of clypeus. Dentition 3:3. Maxillary palp count 2. Antenna length 706. Radicle pronounced. Scape laterally flattened, only 2.25 × as long as broad. Pedicel semiglobular, only 1.5 × as long as broad (possible artifact of compression), 0.5 × as long as scape (Fig. 10C ). All flagellomeres are longer than wide with fu1 longest one, length 98, about 3.75 as long as wide, fu10 about 1.5 × as long as broad. Clava 2-segmented, 2.8 × as long as broad (Fig. 10C ). Micropilosity present on all claval segments (Fig. 10C ). Mesosoma length 334. Notch in posterior most part of lateral panel of pronotum dorsal to prepectus with prothoracic spiracle (?) (Fig. 10D :msp). Mesonotum 238. Prepectus externally visible, thin, dorsally overlapped by lateral panel of pronotum, ventral portion curved anteriorly (Fig. 10C :pre). Notauli present as depression (Fig. 10D ). Mesopleuron elongate, 1.5 × as long as wide (250:164). Axillular rim with sharp carina delimiting mesoscutellum from frenum. Bubble obscuring propodeo-metanotal complex. Wings. Fore wing 2.8 × longer than wide (981:343). Longest marginal seta 31. Cubital vein 174 (sclerotized part) and extending as pigmented fold beyond length of postmarginal vein. Basal vein 43, strongly sclerotized. Submarginal vein length 372, with 7 admarginal setae, basalmost 2 being longest. Marginal vein length 110, width 27, with 6 admarginal setae. Stigmal vein 61, at ≈85° to wing edge. Uncus with 5 uncal sensillae. Postmarginal vein 0.8 × as long as marginal vein, tapering. Costal cell of fore wing very narrow. Hind wing slender, 10.6 × longer than wide (647:61) (Fig. 10B ). Legs. Basitarsomere equal in length to tarsomere 2-4; basitarsal comb absent. Arolium of pretarsus elongate, extending further distally than tarsal claws (Fig. 10E :aro). Metasoma length 555. Petiole obscured by bubble, however slendering of propodeum and expanding of metasoma suggests a constricted petiole. Metasoma with 6 countable tergal segments (Mt2-7) and syntergum (Mt8+9); 2 enlarged sternal segments countable. Hypopygium with longitudinal row of 6 setae along edge, concave distally and reaching end of Mt7. Syntergum relatively short (141), only ⅓ length of extruded ovipositor (Fig. 10F ). Ovipositor length 383, tip of ovipositor with 5 teeth (Fig. 10F :ov); ovipositor sheaths equal in length to ovipositor, ovipositor sheath flattened but equal width along entire length (Fig. 10F :3v).

Male. Unknown.

Material examined.

Holotype: female, Hammana / Mdeyrij , Caza Baabda , Mouhafazet Mount Lebanon; lower Barremian. In amber mounted in Canada Balsam. Deposited at Natural History Museum of the Lebanese University, accession/specimen number: 1228.

Type condition.

A large bubble obscures the posterior of the propodeum and petiole. The head is damaged at the lateral clypeal line.

Etymology.

The specific epithet is derived from the Latin word for ‘short’, referring to the comparatively short syntergum relative to the other species in the genus.

Figures

Figure 10. Cretaxenomerus brevis, holotype A lateral habitus B fore and hind wing C head, ventrolateral, and antenna D mesonotum, dorsolateral E fore leg F ovipositor complex and terminal abdominal segments. Scale bars: 500 µm (A); 200 µm (B, C); 150 µm (D-F). aro = arolium; hw = hind wing.