Amblybolini, 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

Key to the accepted four genera of Amblybolini tribus nova:

1(2) Metazonae smooth, only slightly vaulted at most............................................................. 3

2(1) Metazonae strongly carinate ( Figs 1 and 4 )................................................................. 5

3(4) Antennal groove/cavity below eyes shallow. Posterior gonopods suberect, devoid of a central sternal rudiment.... Amblybolus

4(3) Antennal groove/cavity below eyes very deep and clear-cut. Posterior gonopods strongly curved and showing a small, but distinct, central, sternal rudiment................................................................ Atlanticobolus

5(6) Metatergal crests simple, even, not concave in the middle. Prominent prefemoral or coxal protuberances present on male legs 2 and 3, respectively. Anterior gonopods subtriangular in overall shape ( Figs 4–7 ).................. Costabolus gen. nov.

6(5) Metatergal crests bimodal, slightly, but clearly concave in the middle. Male legs 2 and 3 devoid of prefemoral or coxal protuberances. Anterior gonopods more complex and palm-shaped in overall shape ( Figs 1–3 ).............. Carinobolu s gen. nov.

Figures

FIGURE 1. Carinobolus complex sp. nov., male holotype (NHMD). A. Habitus, lateral view. B & C. Anterior part of body, lateral and ventral views, respectively. D. Posterior part of body, ventral view. Scale bars: 4 mm (A), 1 mm (B–D).

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 4. Costabolus baculus sp. nov., male holotype (VNHM 198). A & B. Habitus, lateral and ventral views, respectively. Scale bars: 5 mm.