Costabolus, Golovatch & Vandenspiegel, 2022

Golovatch, Sergei & Vandenspiegel, Didier, 2022, Carinobolus gen. nov. and Costabolus gen. nov., two new, remarkably crested monospecific genera of spirobolidan millipedes from WestAfrica, with the proposal of a new tribe, Amblybolini tribus nova (Diplopoda, Spirobolida, Pachybolidae), Zootaxa 5150 (1), pp. 97-110 : 108

Costabolus gen. nov.

Type species: Costabolus baculus sp. nov., from Nigeria, by present designation.

No other species known.

Diagnosis. A tribe of the family Pachybolidae characterized by the following putative apomorphies or synapomorphies:

- incisura lateralis closed ( Figs 2B , 5D ), a synapomorphy shared with Pachybolini ( Wesener et al. 2008);

- setae on lamellae linguales apical ( Figs 2D , 5H ), a synapomorphy shared with Pachybolini ( Wesener et al. 2008);

- vulva subreniform and bivalve ( Fig. 7A, B ), a synapomorphy shared with Pachybolini ( Wesener et al. 2008), but devoid of a central ridge, this being an apparent plesiomorphy.

- both posterior gonopods mostly connected by a tiny sternite, each distinctly biarticulate near midlength ( Figs 3G–I , 6J–K ), telopodite clearly twisted based on a subtransverse course of the seminal groove dividing the coxite and telopodite.

Figures

FIGURE 2. Carinobolus complex sp. nov., male paratype (RMCA). A & B. Head, frontal and lateral views, respectively. C. Tip of antenna, sublateral view. D. Gnathochilarium, ventral view. E, F & G. Right mandible, submesal, mesal and subfrontal views, respectively. H. Anterior part of body, lateral view. I. Midbody rings with ozopores (oz), lateral view. J. A midbody metazona showing bimodal crests. K & L. Posterior part of body, lateral and ventral views, respectively. M. Cross-section of midbody ring, frontal view. N. Details of a midbody ring, lateral view. O. Limbus of a midbody ring, lateral view. Abbreviations: et, external tooth; it, internal teeth; lt, lateral tooth; mp, molar plate; oz, ozopore; pl, pectinate lamella. Scale bars: 500 µm (A, I, K, L, M), 200 µm (B, D, H, J), 100 µm (C, E, F, G, N), 10 µm (O).

FIGURE 3. Carinobolus complex sp. nov., male paratype (RMCA). A. Midbody leg, lateral view. B. Apical parts of a postgonopodal leg with a tarsal pad, subventral view. C. First three legs, ventrocaudal view. D & E. Anterior gonopods, posterior and anterior views, respectively. F. Left anterior gonopod, lateral view. G. Right posterior gonopod, lateral view. H. Posterior gonopods, caudal view. I. Drawing of right posterior gonopod, caudal view. Abbreviations: ap, antero-apical process; cx1, coxite of anterior gonopod; cx2, coxite of posterior gonopod; hp, basal projection of prefemur 2; pa, tarsal pad; sl, solenomere; st, sternite; t1 and t2, telopoditomeres 1 and 2; tl, telopodite. Scale bars: 200 µm (A, E, F, G), 50 µm (B), 500 µm (C, D), 0.5 mm (H, I).

FIGURE 5. Costabolus baculus sp. nov., male paratype (VNHM 198). A & B. Head, lateral and frontal views, respectively. C. Tip of antenna. D. Left antenna, lateral view. E. Clypeus, frontolateral view. F & G. Mandible, ventral and mesal views, respectively. H. Gnathochilarium, ventral view. I. Right lateral margin of collum, lateral view. J. A midbody metazona. K. Ozopore. L. Limbus of a midbody ring. M. Posterior part of body, ventral view. N & O. Midbody legs, ventral and lateral views, respectively. P. Tarsus of a midbody leg, lateral view. Abbreviations: et, external tooth; it, internal teeth; lt, lateral tooth; mp, molar plate oz, ozopore; pa, tarsal pad; pl, pectinate lamella. Scale bars: 500 µm (A, B), 100 µm (D, E, F, G), 50 µm (C, P), 200 µm (L, H, J, K, N, O), 10 µm (L).

FIGURE 6. Costabolus baculus sp. nov., male paratype (VNHM 198). A. Anterior part of body, ventral view. B. Coxal projections on leg-pairs 2 and 3. C. Leg-pair 2, posterior view. D. Leg-pair 3, posterior view. E-I. Everted gonopod block, anterior, ventrolateral, ventral, posterior and posterolateral views, respectively. J. Right posterior gonopod, lateral view. K. Drawing of left posterior gonopod, caudal view. Abbreviations: 1, median membranous area of telopodite; 2, lateral sclerotized area of telopodite; cx1, coxite of anterior gonopod; cx2, coxite of posterior gonopod; pg, posterior gonopod; hp, basal projection of prefemur 2; st, sternite; sl, solenomere; t1 and t2, telopoditomeres 1 and 2 of anterior gonopod; tl, telopodite of posterior gonopod. Scale bars: 500 µm (A, C), 100 µm (B), 200 µm (D, E–K).

FIGURE 7. Costabolus baculus sp. nov., female paratype (VMNH 154). A. Ventral view of both vulvae, B. Left vulva, lateral view. Abbreviations: av, anterior valve; cx, coxite of leg 1; cxv, coxite of vulva; o, operculum; pv, posterior valve. Scale bars: 500 µm (A), 200 µm (B).