Coryphomimus, Yin, 2022

Yin, Zi-Wei, 2022, The Batrisini of Tibet: unveiling an enigmatic ant-loving beetle diversity at Earth’s “ Third Pole ” (Coleoptera, Staphylinidae, Pselaphinae), Zootaxa 5111 (1), pp. 1-211 : 94-98

Coryphomimus gen. nov.

( Figs 40–42 )

Chinese common name: ṈỀȁà甲¤

Type species. Coryphomimus levigatus sp. nov. (by present designation).

Diagnosis. Head roundly-triangular; lacking sulcus connecting vertexal foveae, lacking distinct frontal rostrum. Pronotum moderately expanded laterally, broad median longitudinal impression with carinate margins, with discal and lateral longitudinal carinae, disc lacking spines or denticles, with large, setose lateral antebasal, anterolateral and antero-hypomeral foveae, both inner and outer pair of small basolateral foveae present. Elytra with three basal foveae, inner two close, with long discal stria, subhumeral fovea and marginal stria present. Abdomen with tergite 1 (IV) longer than 2–3 (V–VI) combined, constricted near base, with complete inner and outer marginal carinae. Aedeagus stout, with long basoventral projection.

Description. Body length 1.9–2.2 mm; habitus ( Fig. 42A ) elongate; dorsal surface with scattered exceptionally long setae and normal pubescence; antenna relatively elongate, extending to more than half elytral length when extended posteriorly.

Head ( Fig. 40A–C ) roundly-triangular; lacking distinct frontal rostrum, antennal tubercles strongly raised; vertexal foveae ( Fig. 40A ; vf) relatively small, asetose, lacking sulcus connecting them, mediobasal and lateral carinae present; eyes small, ocular-mandibular carina ( Fig. 40B ; omc) complete, carina branched below eye, extended ventrally and then anteriorly to posteroventral articulation of mandible. Venter with small gular foveae ( Fig. 40C ; gf) originating from shared round opening, gular carina thin; antenna 11-segmented, club formed by three apical antennomeres; maxillary palpus with small palpomere 1, 2 pedunculate basally and broad at apex, 3 triangular, 4 sub-fusiform, with small apical cone.

Pronotum ( Fig. 40D–F ) transverse, lateral margins roundly expanded anterior to middle, convergent apically and constricted at basal 1/2, strongly incised posterior to lateral expansion, anterior margin slightly emarginate, posterior margin slightly curved; lateral antebasal foveae ( Fig. 40D ; laf) large, covered by dense setae, median antebasal fovea reduced to oval impression, with additional pairs of distinct, setose anterolateral and antero-hypomeral foveae ( Fig. 40E ; alf, ahf), two pairs of basolateral foveae present, lacking marginal, discal or antebasal spines/tubercles, median longitudinal ( Fig. 40D ; mls) sulcus broad, with carinate margins, with long discal and short lateral longitudinal carina ( Fig. 40D ; dlc, llc), lacking transverse antebasal sulcus; hypomeral ridge ( Fig. 40E ; hr) complete; prosternum with small lateral procoxal foveae ( Fig. 40F ; lpf).

Elytra truncate at bases, each elytron with three basal foveae ( Fig. 40G ; bef), inner two close, lacking subbasal fovea, with long discal stria ( Fig. 40G ; ds) and complete sutural stria, with subhumeral fovea and carinate marginal sulcus ( Fig. 40G, H ; shf, ms).

Mesoventrite with median foveae ( Fig. 41A ; mmsf) narrowly separated, in transverse opening, with large lateral mesoventral foveae not forked (straight) internally ( Fig. 41A ; lmsf); metaventrite with large, setose lateral coxal foveae ( Fig. 41A ; lmcf), lateral metaventral foveae ( Fig. 41A ; lmtf) in broad, shared opening, posterior margin with small, narrow split at middle; coxae broadly separated.

Abdomen constricted near base; tergite 1 (IV) slightly longer than 2–3 (V–VI) combined, with mediobasal and one pair of basolateral foveae ( Fig. 41B ; mbf, blf )), lacking discal carinae, tergites 2–4 (V–VII) ( Fig. 41C ) each with one pair of small basolateral foveae and thin lateral carinae; sternite 2 (IV) with one pair of mediobasal ( Fig. 41D ; mbf) and two to three pairs of basolateral foveae ( Fig. 41C, D ; blf), sternites 3–5 (V–VII) each with two pairs of basolateral foveae.

Legs moderately elongate, tarsomeres 2 and 3 subequal in length, with one major and one setiform claw.

Males have relatively longer antenna than females, antennomeres 10 and 11 modified; trochanters and mesofemur with spines or projections on ventral margins; sternite 2 (IV) with three pairs of basolateral foveae; aedeagus ( Fig. 42H, I ) asymmetric, stout, with long basoventral projection, median lobe with large basal capsule, dorsal lobe embracing median lobe and with elongate sclerite, parameres reduced to single membranous structure. Female with two pairs of basolateral foveae on sternite 2 (IV); genitalia ( Fig. 42J ) weakly sclerotized.

Comparative notes. Coryphomimus shares with a few species of Coryphomodes Jeannel the lack of marginal spines on the pronotum, and close inner two pairs of basal foveae of the elytra. The new genus differs from Coryphomodes and all other similar genera centered on Tribasodites Jeannel primarily by the presence of large, setose anterolateral and antero-hypomeral foveae of the prothorax; other characters that may bear generic importance are: moderately expanded lateral margins and presence of lateral longitudinal carinae (instead of sulci) of the pronotum, long discal striae of the elytra, and the abdomen is constricted near the base, with tergite 1 (IV) longer than 2 and 3 (V and VI) combined.

Etymology. The generic name is a combination of Greek ‘ koryphç (head, top)’ and ‘ mîmos (imitator, actor)’, indicating the morphological similarity to Coryphomodes . The gender is masculine.

Figures

FIGURE 40. Morphology of Coryphomimus gen. nov. A–C. Head, in dorsal (A), lateral (B) and ventral (C). D–F. Prothorax, in dorsal (D), lateral (E) and ventral (F). G. Left elytron. H. Basal half of elytron, in lateral view.Abbreviations: alf—anterolateral fovea, ahf—antero-hypomeral fovea, bef—basolateral foveae, blf—basolateral fovea, dlc—discal longitudinal carina, ds—discal stria, gc—gular carina, gf—gular fovea, hr—hypomeral ridge, lpf—lateral procoxal fovea, laf—lateral antebasal fovea, llc—lateral longitudinal carina, mbc—mediobasal carina, mls—median longitudinal sulcus, ms—marginal stria, omc—ocularmandibular carina, shf—subhumeral fovea, vf—vertexal fovea. Scale bars: 0.2 mm.

FIGURE 41. Morphology of Coryphomimus gen. nov. A. Meso- and metaventrite. B–D. Abdomen, in dorsal (B), lateral (C) and ventral (D). Abbreviations: blf—basolateral fovea, lmcf—lateral mesocoxal fovea, lmsf—lateral mesoventral fovea, lmtf—lateral metaventral fovea, mbf—mediobasal fovea, mmsf—median mesoventral fovea, s1–6—sternites 1–6 (III–VIII), t1–5—tergites 1–5 (IV–VIII). Scale bars: 0.2 mm in A; 0.3 mm in B–D.

FIGURE 42. Morphology of Coryphomimus levigatus sp. nov. (A–I. Male. J. Female). A. Dorsal habitus. B. Head and pronotum. C. Antennomeres 9–11. D. Antennomere 10, in ventral view. E. Mesotrochanter and base of mesofemur. F. Metatrochanter. G. Sternite 7 (IX). H–I. Aedeagus, lateral (H) and ventral (I). J. Genitalia. Scale bars: 0.5 mm in A; 0.3 mm in B; 0.2 mm in C, H, I; 0.1 mm in D–G, J.