Gubuzhu orientalis X.-T. Xu & C. Waichert, 2025

Gubuzhu orientalis X.-T. Xu & C. Waichert , n. gen., n. sp.

( Figs 1-3 View FIG View FIG View FIG ; 5A View FIG )

urn:lsid:zoobank.org:act:8C8235F1-9160-4914-8934-0BC9BF609564

TYPE MATERIAL. — Holotype. China • 1♀; West China, Xizang Autonomous Region, Naqu City, Shuanghu County, Xiede Village , Xiede locality; 31°58’23”N, 88°25’42”E; Xiede section, Nima Basin, Niubao Formation; Bartonian (Eocene); 4662 m a.m.s.l.; VI.2019; XTBG exped.; XTBG; XDA1-1419A , B . GoogleMaps

Paratype. China • 1♀; same data as for the holotype; XDB3-0935A , B . GoogleMaps

ETYMOLOGY. — From Latin oriēns (‘rising sun’), referring to the known area of occurrence of the species.

TYPE LOCALITY AND STRATIGRAPHY. — Both holotype and paratype were collected at the Xiede locality (northern Kanggale Hill, Tibet, China); Xiede section, Nima Basin, Niubao Formation (see Zhang et al. 2022 for detailed information); Bartonian (Eocene; Fang et al. 2020; Xiong et al. 2022).

DIAGNOSIS. — In female, the third antennal segment is about 3× as long as wide; the clypeus is trapezoidal; the pronotum is rather short; the metatibia bears apical spines-like setae, which are long, distinctly splayed, of irregular lengths and spacing; the forewing has three submarginal cells (1R1, 1Rs and 2Rs), and the vein Cu is distinctly deflected downward at base; the hindwing jugal lobe is large (about 0.70-0.75× the length of Cu cell); and the tergite 6 has dense, stiff, backward-directed bristles.

GENERAL DESCRIPTION

Measurements (in mm)

Body length (excluding antenna) 11.8-14.8 (holotype 14.8; paratype 11.8).

Head. Compound eyes about 2.0-2.2× as long as wide (1.6-2.0 long and 0.7-1.0 wide in maximum); MID = 1.0-1.2; UID = 1.0-1.1; LID = 0.6-0.7; TFD = 3.0 (measured in holotype); FD = 2.6 (measured in holotype); third antennal segment about 2.8-2.9× as long as wide (0.7-0.8 long and 0.2-0.3 wide).

Mesosoma. 1.5× as long as wide (5.2 long and 3.5 wide in maximum;measured in holotype);propodeum 1.6long and3.5wide in maximum (measured in holotype); metafemur about 3.3× as long as wide (2.0-2.7 long and 0.6-0.8 wide in maximum, measured in holotype); the longer metatibial spur 1.7-2.0× as long as third antennal segment (1.3-1.4 long); metabasitarsus 2.3-2.4 long.

Wings. Forewing 3.5-4.1× as long as wide (9.4 long and 2.7 wide in holotype; 8.2-8.3 long and 2.0-2.2 wide in paratype); hind wing 3.6× as long as wide (6.3 long and 1.7 wide in maximum; measured in holotype).

Metasoma. 6.2-7.6 long.

Head ( Figs 1A, B View FIG ; 2 View FIG )

Almost as wide as long; TFD about 1.2× FD; TFD about 2.5× MID; compound eyes large, with inner margin slightly emarginate, 2.0-2.2× as long as wide, UID about 1.4× LID; ocelli in a compact triangle, nearer to each other than to compound eyes; vertex almost straight; clypeus short, trapezoidal, anterior margin straight; antenna elongate, thin, third antennal segment 2.8-2.9× as long as wide.

Mesosoma

Pronotum rather short, while delimitation of pronotum and scutum inconspicuous. Legs slender, metafemur 3.3-3.4× as long as wide (measured in holotype); protibia with one posterior spur (calcar), meso- and metatibia with two spurs; the longer metatibial spur 0.6× metabasitarsus length; metatibia with apical spines-like setae long, distinctly splayed, of irregular lengths and spacing ( Fig. 1I, H View FIG ); foretarsus lacking conspicuous spines on the outer side ( Fig. 5A View FIG ).

Forewing ( Figs 1C, D View FIG ; 3A, B View FIG )

Maximum width 0.2-0.3× its length, with 3 submarginal cells; 2 R 1 cell almost as long as its distance from wing tip; 2Rs cell longer than 1Rs cell; 2m-cu vein slightly bowed toward wing apex, meeting 2Rs cell 0.6× distance from base to apex of cell [i.e., length of the section of the basal posterior edge of 2Rs cell to the insertion of 2m-cu cross-vein (orange arrow on Fig. 3A View FIG ) about 0.6× that of the entire posterior edge of 2Rs cell]; 2m-cu vein arising on Cu longer than or about half the distance from the base of 2M cell to the outer wing margin [i.e., section of Cu located between its insertion of 2cu-a and 2m-cu cross-veins (blue arrow on Fig. 3A View FIG ), longer than or almost as long as the section of Cu located between its insertion of 2m-cu cross-vein to its projected termination on the wing margin (blue fame arrow on Fig. 3A View FIG )]; Cu vein distinctly deflected downward at base (‘de’ on Fig. 3A View FIG ).

Hindwing ( Fig. 1E, F View FIG )

With cu-a cross-vein reaching the M+Cu vein basal to the M/Cu split; jugal lobe very large, about 0.70-0.75× length of Cu cell ( Fig. 1E, F View FIG ; pink arrows on Fig. 3A, B View FIG ).

Metasoma

First segment of metasoma inconspicuous for both specimens. Tergite 6 with dense, stiff, backward-directed bristles ( Fig. 1J, K View FIG ).

Coloration

Integument dark on head and mesosoma, lighter on metasoma; punctuation inconspicuous; forewing ( Fig. 1C, D View FIG ) hyaline, darkened in about 1/4 of the apical portion, and a dark spot at 2/3 of wing length, partially covering cells 2 R 1, 1 R 1 1Rs, 2Rs, and 1M ( Figs 1C View FIG ; 2A View FIG ).

REMARKS ON THE TYPE SERIES

Holotype specimen, XDA 1-1419A,B ( Figs 1A, C, E, G, H, J View FIG ; 2A View FIG ; 5A View FIG ), adpressions in both positive and negative aspects (but indistinguishable as a consequence of rock compression) of a nearly complete body in dorso-ventral orientation. Apex of FW2 partially folded ( Figs 1A View FIG ; 3A View FIG ); FW1 well exposed, partly overlapping HW1 ( Figs 1C View FIG ; 2A View FIG ).Tibia pale, almost invisible except for apical part; legs lack thick spines along length, with spurs, few apical spines on tibia and tarsi ( Fig. 1G, H View FIG ). Forewing coloration is well preserved ( Figs 1C View FIG ; 2A View FIG ).

Paratype specimen, XDB3-0935A, B ( Figs 1 B, D, F, I, K View FIG ; 2B View FIG ), adpression in both positive and negative aspects (but indistinguishable as a consequence of rock compression) of a nearly complete body in lateral orientation.Mouthpart poorly-exposed; antennae apparently detached from torulus; forelegs and one of the mesolegs lacking. Forewings well exposed, overlapping with one of the hindwings (HW2; Figs 1B, F View FIG ; 2B View FIG ). Tibia with at least two spines on the outer surface and unevenly-spaced spines, of unequal length, at the apex ( Fig. 1I View FIG ).

REMARKS

The specimens treated here can confidently be assigned to the family Pompilidae based on a distinctive combination of wing venation characters (see Day 1988; Rodriguez et al. 2017), relatively uniform for the family. The specimens can be further assigned to the Pompilinae owing to the occurrence of: 1) forewing having cell 2M deflected downward at the base (‘de’ on Fig. 1C, D View FIG ); 2) vein M not reaching wing margin; 3) metatibia with apical spines-like setae long, distinctly splayed, of irregular lengths and spacing ( Fig. 1I View FIG ); and 4) eyes not close together beneath antennal socket ( Day 1988). Within the subfamily, an assignment to the Pompilini is indicated by the: 1) forewing with three submarginal cells; 2) pronotum shorter than mesonotum; 3) postero-lateral angles of propodeum not produced backward ( Evans 1949). At the genus level, the Pompilidae as a whole have traditionally been regarded as a taxonomically difficult group, with a systematic framework often based on slight differences or a particular combination of character states, which are often homoplasies ( Wasbauer & Kimsey 1985; Waichert et al. 2015). Within Pompilinae , dense bristles on the tergite 6 of female are present in Anoplius Dufour, 1834 , Anospilus Haupt, 1929 , Lophopompilus Radoszkowski, 1887 ( Pompilini ) and some species of Priochilus Banks, 1944b (Priochilini; Pitts et al. 2006; Wasbauer et al. 2017; note that such bristles occur also in most Pepsinae, the sister-group of Pompilinae ). We justify not placing the new specimens in Anospilus by the later having fine bristles, whereas they are thick in the former. ( Fig. 1J, K View FIG ); moreover, species of Lophopompilus present protarsus with comb ( Loktionov & Lelej 2015), which is lacking in the new specimens ( Fig. 5A View FIG ). Finally, the most distinctive character state to distinguish the specimens XDA 1-1419 and XDB3-0935 from these genera is a much larger hindwing jugal lobe, about 0.70-0.75× the length of Cu cell (pink arrow on Fig. 3A, B View FIG ; in the other genera it is small, at most half the length of the Cu cell, see pink arrow on Fig. 3 View FIG C-E for Anoplius , Anospilus and Priochilus , and see Regan (1923) for Lophopompilus ). Note that, among tribe Pompilini , a large jugal lobe is also present in the genus Chalcochares Banks, 1917 ( Fig. 3F View FIG ). However, in addition to the occurrence (or lack thereof) of dense bristles, the new specimens differ from this genus by, in the hind wing, the cu-a cross-vein reaches the M+Cu vein basal to the M/Cu split ( Figs 1E, F View FIG ; 3A, B View FIG ), whereas in Chalcochares the cu-a cross-vein meets M+Cu at the M/Cu split ( Fig. 3F View FIG ).

We also carried out a comparison with other, known fossil Pompilinae , mostly based on forewing venation. According to the revision by Rodriguez et al. (2017), six species can be confidently assigned to the subfamily, including Agenioideus saxigenus ( Cockerell, 1908) , Anoplius planeta Rodriguez & Pitts, 2016 in Rodriguez et al. (2016b), Tainopompilus argentum Rodriguez & Pitts, 2016 in Rodriguez et al. (2016b), Tenthredinites bifasciata Meunier, 1915 , Pompilinites coquandi ( Theobald, 1937) and Pompilinites depressus ( Statz, 1936) (with the taxonomic concept ‘ Pompilinites ’ to be understood as a ‘collective group’ including fossil species belonging to Pompilinae but which formal generic placement cannot be assessed; Rodriguez et al. 2017). The proposed new species can be easily distinguished from Agenioideus saxigenus by its 2m-cu vein meeting the 2Rs cell 0.6× distance from base to apex of the 2Rs cell ( Fig. 3A, B View FIG ), while in the latter the 2m-cu vein meets the 2Rs cell 0.95× distance from base to apex of the 2Rs cell ( Rodriguez et al. 2017: fig. 4A). The proposed new species differs from Anoplius planeta by its 2m-cu vein arises on Cu cell longer than or about half the distance from the base of the 2M cell to the outer margin (see blue arrows on Fig. 3A, B View FIG ), while in the latter the 2m-cu vein arises on the Cu cell less than half the distance from the base of the 2M cell to the outer wing margin ( Rodriguez et al. 2016b). In Tainopompilus argentum and Pompilinites depressus , the pterostigma is larger than, or about half the length of the 2 R 1 cell, respectively ( Rodriguez et al. 2016b: fig. 2; Statz 1936), while it is less than the third of the length of the 2 R 1 cell in the new specimens. The case of Tenthredinites bifasciata is difficult, as the location of the holotype is undetermined ( Rodriguez et al. 2017), and the available data is limited, with, besides the original description ( Meunier 1915), a revision by Theobald (1937). Moreover, according to this author, it may represent the female of Pompilites fasciatus ( Theobald, 1937) , which may not be a Pompilinae ( Rodriguez et al. 2017). However, forewing coloration pattern, at least, indicate that the new specimens differ from this species (in which the forewing has two dark stripes, with one covering the base of the 1 R 1, 1M and 2Cu cells, and the other partially covering the 2 R 1, 1Rs, 2Rs and 2M cells). Lastly, the 2m-cu vein is straight in Pompilinites coquandi ( Theobald, 1937) , while it is slightly bowed towards the wing apex in the new specimens.

In summary, based on the unique combination of character states mentioned above, the erection of a new genus and species is supported.