Abiliodesmus, Bouzan & Iniesta & Brescovit, 2021

Bouzan, Rodrigo Salvador, Iniesta, Luiz Felipe M. & Brescovit, Antonio Domingos, 2021, Cladistic analysis and taxonomic review of the millipede tribe Arthrosolaenomeridini Hoffman, 1976 (Polydesmida: Chelodesmidae), Zootaxa 4970 (2), pp. 201-256 : 235-236

Abiliodesmus n. gen.

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Type species. Arthrosolaenomeris planaltensis Schubart, 1960 .

Diagnosis. Males of Abiliodesmus n.gen. differ from those of other Arthrosolaenomeridini genera by the combination of the following characters: slight dorsal lobe on leg prefemur ( Figs 31C–D ); lateral macrosetae dispersed on the gonocoxae, in mesal view ( Fig. 32F ); cingulum with a basal position ( Fig. 20F ); and presence of a membranous lateral flap at the apex of the solenomere ( Fig. 22D ) (absent in Abiliodesmus mapinguari n. sp.).

Description. General characters: Body length between 34.63 mm ( A. defensor comb. nov.) and 69.15 mm ( A. mapinguari n. sp.). Coloration (specimens long preserved in 70% ethanol) variable between species, ranging from ocher to reddish brown, paranota tip and posterior border of the metaterga slightly whitish. Gnathochilarium: lingual plate covered completely by sparsely setae; mentum only centrally covered by setae, with smooth edges and stipes covered by sparsely setae. Body alignment of paranota in posterior view curved ventrally (straight in A. cataractae comb. nov and A. defensor comb. nov.). Sternite of the fourth segment with a pair of projections, sternite of the fifth with two pairs of projections covered by setae, the posterior pair less conspicuous. Sternite of sixth body ring without ventral projections (present in A. mapinguari n. sp.); seventh with a pair of ventral projections (absent in A. cataractae comb. nov.) and post-gonopodal sternites with two pairs of acuminate ventral projections ( Fig. 30F ) (absent in A. cataractae comb. nov. and rounded in A. mapinguari n. sp.). Paranota form: round to slightly rectangular ( Figs 20B , 23B ). Legs: without modifications beyond a slight dorsal lobe on prefemur; thin setae on the ventral part of the podomeres in the anterior legs ( Fig. 31D ).

Male characters: Leg pair of the third body ring with the coxae presenting the rectangular genital papilla. Gonopod aperture on seventh body ring with the posterior margin excavated and with a small projection (absent in A. mapinguari n. sp.). Gonopods: gonocoxae equivalent to about half the length of the telopodite, cylindrical, without a spiniform process. Prefemoral process: elongate and thin with a dorso-basal process ( Fig. 20D ). Cingulum in a basal position ( Fig. 20F ). Solenomere long with apex ascending and lateral membranous expansion ( Fig. 21D ) (absent in A. mapinguari n. sp.).

Female characters: Vulvae ( Figs 24E–F ): oval-shaped, having different proportions in lateral view.

Distribution. States of Tocantins, Goiás and São Paulo, Brazil ( Fig. 25 ).

Etymology. The genus name is taken as a noun in apposition. Name in honor of a very important person in the life of the first author, considered a great storyteller, with the combining stem “-desmus,” meaning band, commonly used in generic names in Polydesmida .

Composition. Abiliodesmus planaltensis comb. nov. ( Schubart, 1960); Abiliodesmus cataractae comb. nov. ( Hoffman, 1976); Abiliodesmus defensor comb. nov. ( Hoffman, 1976); Abiliodesmus mapinguari n. sp.

Figures

FIGURE 20. Abiliodesmus planaltensis (Schubart, 1960) comb. nov. (holotype, MZSP 1086), dorsal views of anterior (A), midbody (B) and posterior (C) body rings. Scale bars: 2 mm. Left gonopod. (D), mesal view; (E), ventral view; (F), ectal view. Scale bars: 1 mm. Abbreviations: C, cingulum; PfP, prefemoral process; S, solenomere.

FIGURE 21. Abiliodesmus cataractae (Hoffman, 1976) comb. nov. (holotype, MZSP 1065), dorsal views of anterior (A), midbody (B) and posterior (C) body rings. Scale bars: 2 mm. Left gonopod (Modified by Hoffman, 1976). (D), mesal view; (E), ectal view. Scale bars: 0,5 mm. Abbreviations: C, cingulum; PfP, prefemoral process; S, solenomere.

FIGURE 22. Abiliodesmus defensor (Hoffman, 1976) comb. nov. (holotype, MZSP 1067), dorsal views of anterior (A), midbody (B) and posterior (C) body rings. Scale bars: 2 mm. Left gonopod. (D), mesal view; (E), ventral view; (F), ectal view. Scale bars: 0,5 mm. Abbreviations: C, cingulum; PfP, prefemoral process; S, solenomere.

FIGURE 23. Abiliodesmus mapinguari n. sp. (holotype, IBSP 1699), dorsal views of anterior (A), midbody (B) and posterior (C) body rings. Scale bars: 2 mm. Left gonopod. (D), mesal view; (E), ventral view; (F), ectal view. Scale bars: 1 mm.Abbreviations: C, cingulum; PfP, prefemoral process; S, solenomere.

FIGURE 24. Left vulva. Gangugia tapirapensis Schubart, 1947 (paralectotype, MZSP 1070): (A), ventral view; (B), lateral view. Gangugia mula n. sp. (paratype, IBSP 276): (C), ventral view; (D), lateral view. Abiliodesmus planaltensis (Schubart, 1960) comb. nov. (IBSP 3569): (E), ventral view; (F), lateral view. Abiliodesmus cataractae (Hoffman, 1976) comb. nov. (paratype, MZSP 1066). (G), ventral view; (H), lateral view. Scale bars: 0,5 mm.Abbreviations: EV, external valve; IV, internal valve; Op, operculum.

FIGURE 25. Distribution map of Abiliodesmus n. gen. species.

FIGURE 30. Sternites, ventral projections. A) Arthrosolaenomeris pantanalensis Schubart, 1943 (IBSP 530), 6th body ring; B) Dioplosternus salvatrix Hoffman, 2005 (IBSP 1084), 6th body ring; C) Arthrosolaenomeris saci n. sp. (IBSP 1148), 7th body ring; D) Folcloredesmus thomasi n. sp. (CZUFMT 833), 9th body ring; E) A. saci n. sp., 9th body ring; F) Abiliodesmus planaltensis (Schubart, 1960) comb. nov. (IBSP 3570), 9th body ring. Scale bars: A–C, 1 mm.; D, 0,5 mm.; E, 0,3 mm.; F, 0,3 mm.

FIGURE 31. Legs. A) Arthrosolaenomeris pantanalensis Schubart, 1943 (IBSP 530); B) Gangugia boto n. sp. (holotype, IBSP 7539); C–D) Abiliodesmus planaltensis (Schubart, 1960) comb. nov. (IBSP 3570); E–F) Gangugia tapirapensis Schubart, 1947 (MNRJ 12008). Scale bars: A) 2 mm.; B) 1 mm.; C) 1 mm.; D) 1 mm.; E) 500 µm.; F)1 mm. Abbreviations: co, coxae; f, femur; prf, prefemur; pst, postfemur; t, tarsus; tb, tibia; tc; tarsal claw.

FIGURE 32. Gonocoxae.A) Arthrosolaenomeris pantanalensis Schubart, 1943 (IBSP 530); B) Gangugia tapirapensis Schubart, 1947 (MNRJ 12008); C) Folcloredesmus thomasi n. sp. (CZUFMT 833); D) A. pantanalensis Schubart, 1943 (IBSP 530); E) F. thomasi n. sp. (CZUFMT 833); F) Abiliodesmus mapinguari n. sp. (CZUFMT 836). Scale bars: A–B, D–F) 1 mm.; C) 0,2 mm. Abbreviations: Cx, gonocoxae; RE, rounded extension; SP, spiniform process.