Geonigidius Xin, Gong, Zhong & Qi, 2025
|
publication ID |
https://doi.org/10.11646/zootaxa.5728.3.4 |
|
publication LSID |
lsid:zoobank.org:pub:2C2CDF3F-076E-4C0A-A24D-065691669AD3 |
|
persistent identifier |
https://treatment.plazi.org/id/03CAA25F-D368-C520-FF70-AD462EFD0E42 |
|
treatment provided by |
Plazi |
|
scientific name |
Geonigidius Xin, Gong, Zhong & Qi |
| status |
gen. nov. |
Geonigidius Xin, Gong, Zhong & Qi , gen. nov.
Chinese common name: üaēạṁşȃ http://zoobank.org/ urn:lsid:zoobank.org:act:
( Figs. 1–10 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 )
Type species. Geonigidius sinensis Xin, Gong, Zhong & Qi , sp. nov., by present designation.
Diagnosis. The new genus can be easily identified as a member of the tribe Figulini Burmeister, 1847 ( Huang & Chen 2017) by the following characters: mandibles 0.6–1.2 times as long as head; scutellum distinctly longer than wide; elytra with deep longitudinal grooves; tarsi short, and the empodium between each pair of claws lacking a rod-like structure, replaced by a single seta; dorsal surface of the median lobe of aedeagus non-expandable; median lobe of aedeagus without pedestal crossbar. The presence of a vertical dorsal appendage on the mandible indicates that it is most closely related to Nigidius MacLeay, 1819 , Novonigidius Dudich, 1923 , Ganelius Benesh, 1955 and Dinonigidius De Lisle, 1974 but can be easily distinguished by the following features: 1) body more robust ( Figs. 1–2 View FIGURE 1 View FIGURE 2 ). 2) head broad and long, dorsal surface without a forward-pointing horn, slightly wider but slightly shorter than the pronotum ( Fig. 3 View FIGURE 3 ). 3) eyes located on both sides of the median length of the head; ocular canthus slender; the length of the postocular margin significantly longer than the preocular margin ( Fig. 3 View FIGURE 3 ). 4) dorsal appendage of the mandible distinctly asymmetrical ( Fig. 4 View FIGURE 4 ). 5) pronotum without medial groove, outer margins regularly rounded, lateral lobes almost absent ( Fig. 5A View FIGURE 5 ); 6) the distance between the prothorax and metathorax relatively large, resulting in incomplete closure of the two segments ( Figs. 1–2 View FIGURE 1 View FIGURE 2 ; 9B–C View FIGURE 9 ). 7) elytra extremely short and thick, length not exceeding the sum of the head and pronotum ( Figs. 1–2 View FIGURE 1 View FIGURE 2 , 5C View FIGURE 5 ), showing a strongly arched shape in lateral view ( Fig. 6C View FIGURE 6 ); carina VII prominently elevated, and completely obscures the lateral margin of the elytron in dorsal view ( Figs. 5C View FIGURE 5 ; 6D–E View FIGURE 6 ). 8) hindwings atrophied into a strip-like form ( Fig. 6B View FIGURE 6 ). 9) flagellum of aedeagus very long, longer than 5 times the length of the aedeagus ( Fig. 8 View FIGURE 8 ).
Description. Habitus ( Figs. 1–2 View FIGURE 1 View FIGURE 2 ). Body stubby, relatively large-sized compared to other genera within the same tribe; exhibits a uniform black coloration with distinct luster, without conspicuous vestiture on surface of body.
Head ( Figs. 3–4 View FIGURE 3 View FIGURE 4 ) large. Accounting for a significant proportion of the entire body, distinctly wider but slightly shorter than the pronotum; dorsal surface with a pair of short longitudinal carinae behind the anterior margin of the head, which are distinctly elevated and directed posterolaterally; two evident point-like protrusions symmetrically present on both sides basally. Eyes small located on the outer margins of the median length of the head. Canthus thin and just completely dividing the eye. Clypeolabrum moderately long. Mandible stout, dorsal appendage of mandible bilaterally asymmetrical, with a strong upward curvature that nearly perpendicular to the head. Basal part of mandible short. Mentum transverse and bilobate. Ventral side of apical half of the scape covered with irregular and deep punctures. Antennal club with 3 antennomeres; antennomeres VIII–IX subtriangular; antennomere X semi-elliptic.
Pronotum ( Fig. 5A View FIGURE 5 ) transverse, slightly shorter and narrower than head; dorsal surface without a central depression.Anterior margin presents a bisinuate shape; lateral margins relatively straight and slightly serrated in the middle; posterior margin curves rounded and shows a smooth outline. Anterior angles obtuse, lateral lobes almost absent, posterior angles rounded.
Prosternum ( Fig. 5B View FIGURE 5 ) covered with irregular and deep punctures. A considerable distance between the prothorax and metathorax results in the incomplete closure.
Elytra ( Fig. 5C View FIGURE 5 ; 6C–E View FIGURE 6 ) short and broad. Distinctly arched in lateral view; with obvious longitudinal carinae, and dense rows of punctures varying in size.
Metasternum and visible abdominal ventrites ( Fig. 5D View FIGURE 5 ) with dense punctures varying in size.
Scutellum ( Fig. 5E View FIGURE 5 ) tiny, trapezoidal and punctate.
Legs. Outer margin of tibiae with different-sized protuberances. Tarsi short, with a small ratio of length to tibiae, a single seta between pair of claws ( Fig. 5F View FIGURE 5 ).
Hindwings ( Fig. 6A–B View FIGURE 6 ) strongly atrophied, with venation reduced and simplified.
Abdomen and aedeagus. Abdominal tergite VIII ( Fig. 7A View FIGURE 7 ), abdominal ventrite VIII ( Fig. 7B View FIGURE 7 ) and abdominal segment IX ( Fig. 7C–E View FIGURE 7 ) see the corresponding figure. Aedeagus ( Fig. 8A–E View FIGURE 8 ) consistent with the new species description.
Etymology. The generic name, derived from the prefix geo- in reference to “geophile” reflects the species’ inferred ground-dwelling habit, as evidenced by its brachypterous morphological characteristics; and the closely related genus Nigidius .
Distribution. China ( Xizang) ( Fig. 10 View FIGURE 10 ).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.