Trifionyximus cracens Lepeco & Melo, 2022

Lepeco, Anderson, Barbosa, Diego N. & Melo, Gabriel A. R., 2022, A remarkable new family of stinging wasps from the Cretaceous of Myanmar and China (Hymenoptera, Aculeata), Journal of Hymenoptera Research 94, pp. 163-190 : 163

† Trifionyximus cracens Lepeco & Melo sp. nov.

Fig. 6

Type material.

Holotype female in amber piece DZUP Bur-828. The specimen is fully articulated, but part of the right antenna was sanded off. The right forewing apex is fragmented. The left side of the head, the posterior portion of the mesosoma and parts of the metasoma are covered by calcite. There are no syninclusions except for scattered debris. The paratype male is in amber piece DZUP Bur-1386. The specimen is fully articulated, but parts of the mesosoma and the legs are diaphanized. Part of the right antenna was sanded off during preparation. A large calcite bubble obstructs the view of part of the left side of the mesosoma. Syninclusions: a small psocid.

Diagnosis.

As for the genus.

Description.

Female Holotype. Measurements: approximate body length: 3.6 mm; maximum head length: 0.7 mm; approximate forewing length: 1.9 mm. Color. Poorly preserved, apparently dark brown. Wings hyaline, veins brown. Pubescence. Head sparsely covered with short setae. Forewing with homogeneous coverage of tiny setae; anterior margin with dense tiny setae, setae as long as half width of veins C+Sc+R. Sculpturing. Smooth, where preserved. Structure. Maxillary palp with at least three palpomeres. Labial palp not distinguishable. Mandible quadridentate, with three preapical teeth with similar sizes, lower tooth larger than preapical teeth. Clypeus disc about as wide as long, far smaller than compound eye. Frons without carina adjacent to inner orbit; dorsal rim of antennal socket without carina directed towards frons. Mid ocellus separated from lateral ocelli by about its diameter. Lateral ocellus distanced from inner orbit of eye by about ocellar triangle length. Vertex extending behind lateral ocelli for about the width of mid ocellus. Hypostomal bridge 3 times as long as basal mandibular width. Scape about twice as long as maximum width; pedicel about 1.5 times as long as F1. Metapostnotum obstructed. Profemur about 1.2 times as long as maximum width. Tibial spur formula 1-2-2. Basitarsomere of fore leg as long as 0.5 times protibial length. Basitarsomere of hind leg about as long as 0.7 times metatibial length. Tarsal claws trifid.

Male Paratype. As for the female, except: Measurements: approximate body length: 3.0 mm; maximum head length: 0.5 mm; maximum head width: 0.6 mm; medial clypeus length: 0.1 mm; approximate forewing length: 1.8 mm. Color. Head black. Color not preserved in legs and mesosoma, due to diaphanization. Metasomal sclerites apparently dark brown. Wings hyaline, slightly darkened near marginal cell, veins dark brown. Pubescence. Head, mesosoma and most of metasoma apparently glabrous. Apical metasomal sclerites with sparse erect setae. Sculpturing. Smooth, where preserved. Structure. Upper tooth of mandible smaller than lower tooth. Scape about 3 times as long as maximum width. Profemur about twice as long as maximum width.

Etymology.

From the Latin cracens, meaning “slender”, in allusion to the body shape of the type specimens. The name is an adjective.

Figures

Figure 6. † Trifionyximus cracens sp. nov. A, B holotype female (DZUP Bur- 828) A habitus, dorsolateral view B dorsolateral view of head and mesosoma C-F paratype male (DZUP Bur- 1386) C habitus, lateral view D head, lateral view E forewing. Scale bar: 1 mm (A, C); 0.5 mm (B); 0.2 mm (D); 0.4 mm (E).