Zoosphaerium neptunus (Butler, 1872)

Wesener, Thomas & Wägele, Johann-Wolfgang, 2008, The giant pill-millipedes of Madagascar: revision of the genus Zoosphaerium (Myriapoda, Diplopoda, Sphaerotheriida), Zoosystema 30 (1), pp. 5-85 : 10

Zoosphaerium neptunus species-group

SPECIES INCLUDED. — Zoosphaerium neptunus ( Butler, 1872) ; Z. campanulatum (de Saussure & Zehntner, 1897) .

DISTRIBUTION. — Rainforest and montane rainforests on Madagascar, particularly in the northern half of the island (Fig.).

DIAGNOSIS. — These Malagasy giant pill-millipede species share almost identical anterior and posterior telopods ( Figs 2 A-I; 7E-H) and furthermore in males a more or less bell-shaped anal shield ( Figs 1A ; 7D ). All species included possess 2 locking carinae of identical size on the ventral side of the anal shield ( Figs 1C, D ; 7B ). The third joint of the posterior telopods is elongated, straight and without any trace of sclerotized teeth, lobes or spines, which is a unique feature in sphaerotheriids ( Figs 2F, G ; 7G, H ). The process of second joint is long, slender, curved towards the third joint and without spines ( Figs 2F, G ; 7G, H ). Similarities can also be found in the anterior telopods, which are elongated in appearance, all joints being longer than wide ( Figs 2 A-E; 7E, F). A phylogenetic analysis will be necessary to confirm if the neptunus -group represents a monophyletic group to be kept separately from the other Malagasy sphaerotheriids. The missing sex of Z. campanulatum is especially necessary to solve this problem.

Figures

FIG. 2. — Zoosphaerium neptunus (Butler,1872):A-C, right anterior telopod (lectotype of Z.pygidiale n. syn.);A, posterior view;B, inner view; C, anterior view; D, E, right anterior telopod (holotype of Z. digitale n. syn.); D, anterior view; E, posterior view; F, G, posterior telopods (lectotype of Z. pygidiale n. syn.); F, posterior view; G, anterior view; H, I, posterior telopods (holotype of Z. digitale n. syn.); H, anterior view; I, posterior view. Scale bars: 1 mm.

FIG. 1. — Zoosphaerium neptunus (Butler, 1872): A-C ♂ (MNHN CB020); A, habitus; B, coxa of 1st left leg with 1st stigma-carrying plate; C, posterior body end with anal shield, ventral view, last three leg pairs and telopods removed; D, closing ledges of anal shield (holotype of Z. digitale n. syn.); E, closing ledges of anal shield (lectotype of Z. pygidiale n. syn.); F, G, holotype; F, 9th left leg; G, operculum of vulva; H, coxa of 2nd left leg with vulva (paralectotype of Z. pygidiale n. syn.); I, coxa of 2nd left leg with gonopore (MNHN CB020). Abbreviations:12T, 12th tergite; AS, anal shield; Cx, coxa; LT, laterotergite; O, operculum; St, stigma-carrying plate. Scale bars: A, 10 mm; B-I, 1 mm.

FIG. 7. — Zoosphaerium campanulatum (de Saussure & Zehntner, 1897), holotype: A, 10th left leg; B, closing ledges of anal shield; C, coxa of 1st left leg with stigma-carrying plate; D, anal shield, dorsal view; E, F, right anterior telopod; E, posterior view; F, anterior view; G, H, left posterior telopod; G, 2nd and 3rd joints, anterior view; H, 3rd joint, posterior view. Abbreviations: 12T, 12th tergite; AS, anal shield; Cx, coxa; LT, laterotergite; St, stigma-carrying plate. Scale bars: A-C, 1 mm; D, 5 mm; E-H, 1 mm.