Riotintobolus anomalus Wesener, 2009

Wesener, Thomas, Enghoff, Henrik & Sierwald, Petra, 2009, Review of the Spirobolida on Madagascar, with descriptions of twelve new genera, including three genera of ' fire millipedes' (Diplopoda), ZooKeys 19 (19), pp. 1-128 : 55-56

Riotintobolus anomalus Wesener , sp. n.

urn:lsid:zoobank.org:act:D393DC52-5565-41B3-BA6E-D8ED7FAE46BA

Material examined: Holotype: 1 ♂ (45 mm long), CAS BLF 5499 , Madagascar, Province Toliara, Réserve Spéciale de Cap Sainte Marie , 12.3 km 262°W Marovato, spiny forest thicket, 200 m, 25°34’54” S, 45°10’6” E, leg. Fisher, Griswold et al., pitfall trap, 11–15.II.2002 . Paratypes:>25 ♂ and ♀, CAS BLF 5499 , same data as previous ; 2 ♂, 3 ♀, CAS BLF 5651 , same data as previous, but 160 m, 25°35’40” S, 45°8’49” E, leg. Fisher, Griswold et al., malaise trap, 13–19.II.2002 .

Other material examined: 1 ♀, CAS BLF 5503 , Réserve Spéciale de Cap Sainte Marie , spiny forest thicket, 200 m, 25°34’54” S, 45°10’6” E, leg. Fisher, Griswold, et al., 11–15.II.2002 ; 1 ♂, CAS BLF 5758 , Madagascar, Province Toliara, Mahafaly Plateau , 6.2 km 74°ENE Itampolo, spiny forest thicket, 80 m, 24°39’13” S, 43°59’48” E, leg. Fisher, Griswold et al., sifted litter, 21–25.II.2002 ; 2 ♂, CAS BLF 5762 , same data as previous, but hand collecting ; 13 ♂, 6 ♀, CAS BLF 5763 , same data as previous, but pitfall trap ; 1 ♂, MNHN, Madagascar, leg. Petit, 24–1922, envoi vi, entrée 24–1922 ; 1 ♂, CASENT 9032805 , Province Toliara, Lake Ranobe , spiny forest, 30 m, 23°2.941’ S, 43°36.635’ E, leg. Frontier Wilderness Project, 21–28.I.2003 .

Differential diagnosis: R. anomalus is the only known species of Riotintobolus where a sharp-edged preanal process and well-developed lips are absent. Furthermore it is the only species with male tarsal pads on every leg pair. The gonopods of this species are distinct but in some aspects similar to those of R. mandenensis and R. minutus .

Description. Measurements: male holotype with 45 podous and no apodous rings, circa 45 mm long (broken), 4.3 mm wide. Females with 44 or 45 body rings and no apodous ring, up to 51 mm long, 4.6 mm wide.

Coloration light grey with darker posterior margins. Openings of ozopores highlighted with a black spot. Collum and rings dorsally with an extraordinary wide bloodred or rust-red stripe. Antennae and legs dark grey. Eyes with 30–34 ocelli arranged in five rows. Antennae short, protruding in both sexes back to body ring 2 ( Fig. 29B ). Legs reach 0.7 times body diameter, tarsi 3 and beyond in males with tarsal pads ( Fig. 29C ). Preanal process absent, not protruding ( Fig. 29A ). Anal valves small, lips weakly developed ( Fig. 29A ).

Anterior gonopod sternite apically swollen into a wide lobe with a triangular, wellrounded tip ( Fig. 29D ). Sternite tip almost as high as mesal coxite process, latter long, relatively slender, longer than sternite ( Fig. 29D ). Telopodite on posterior side apically with a large triangular retrorse process ( Fig. 29E ), projecting above coxite and telopodite margins ( Fig. 29E ).

Posterior gonopods telopodite laterally with a single, large, finger-shaped process ( Fig. 29F ). Sperm canal discharging into process. Apically, a large membrane present, which extends into two lobes, apically twice as wide as basally ( Fig. 29G ).

Intraspecific variation: no variation inside or in between the Mahafaly and Cap Sainte Marie populations was observed.

Distribution and ecology: this species is currently known from the Mahafaly plateau, the Cap Sainte Marie, and a third, distant location at the Lake Ranobe. All localities are probably the driest places on Madagascar ( Battistini 1972, Moat & Smith 2007).

Etymology: anomalus , adjective, refers to the unusual (for Riotintobolus ) telson of the species.

Figures

Figure 29. Riotintobolus anomalus sp. n., A–C, male (MNHN), D–G male holotype, A telson B right antenna C left midbody leg D anterior gonopod, anterior view E anterior gonopod, posterior view F posterior gonopods, anterior view G posterior gonopods, posterior view. av = anal valves; Cx = coxite; Md = mandible; Pre = preanal ring; St = sternite; sub = subanal scale; T = telopodite. Scale bars = 1 mm.