Riotintobolus bovinus,

Wesener, Thomas, 2020, Ecotone shifts in southern Madagascar: first barcoding data and six new species of the endemic millipede genus Riotintobolus (Spirobolida, Pachybolidae), ZooKeys 953, pp. 1-29: 1

publication ID

http://dx.doi.org/10.3897/zookeys.953.53977

publication LSID

lsid:zoobank.org:pub:BA81E879-88A2-495A-92FB-98D1F2909BA7

persistent identifier

http://treatment.plazi.org/id/5292954C-AE5F-486B-BEDE-941ADA580C1C

taxon LSID

lsid:zoobank.org:act:5292954C-AE5F-486B-BEDE-941ADA580C1C

treatment provided by

ZooKeys by Pensoft

scientific name

Riotintobolus bovinus
status

sp. nov.

Riotintobolus bovinus  sp. nov. Figure 8View Figure 8

Material examined.

1 ♂ holotype, ZFMK MYR940, Madagascar, Province de Toliara, Makay Mts., forêt de galerie, 21°13'27.5"S, 045°19'35.4"E, 531 m, coll. Jean Noel, 30.xi.2010.

Etymology:

bovinus  , after the gonopods which resemble the horns of a cow. Noun in apposition.

Diagnosis.

Riotintobolus bovinus  sp. nov. shares the absence of a projecting epiproct on the telson only with R. anomalus  , R. antafoky  sp. nov., R. tsimelahy  sp. nov., R. mangatsiaka  sp. nov. and R. lavanono  sp. nov. The posterior telopod featuring two slender, sharp projections is only shared with R. tsimelahy  sp. nov., R. mangatsiaka  sp. nov. and R. lavanono  sp. nov. R. bovinus  sp. nov. differs from R. tsimelahy  sp. nov., R. mangatsiaka  sp. nov. and R. lavanono  sp. nov. in a much smaller segment number and size, and strong differences in the posterior telopod, whose telopodite is uniquely shaped with two sharp processes running parallel to one another resembling a bull’s horn. R. bovinus  sp. nov. differs by more than 14% uncorrected p-distance in the COI barcoding gene from all other Riotintobolus  species.

Description.

Measurements: 41+0 segments. Ca. 25 mm long (broken), 2.4 mm wide.

Colour (after 10 years in ethanol): Head and body rings grey, appendages red. Ventral site reddish. Posterior margins of body segments and whole margin of collum black. Anal valves black.

Head: each eye with 24-27 ommatidia in six rows. Incisura lateralis open (Fig. 8AView Figure 8). Labrum with standard three irregular teeth and a single row of 10-12 stout marginal setae. Clypeus with two setiferous foveolae on each side (Fig. 8BView Figure 8). Antennae short, protruding back to segment 3. Length of antennomeres: 1<2>3>4=5=6, second only slightly longer than 3rd. Terminal antennomere with four large sensory cones located together inside a membranous area (Fig. 8BView Figure 8). Antennomere 5 and 6 latero-apically with sensilla basiconica.

Gnathochilarium: lamellae linguales each with two standard setae located behind one another. Stipites each with three apical setae. Endochilarium not dissected.

Mandible: Stipes without projection, well rounded (FIg. 8A, B). Gnathal lobe not dissected.

Collum: smooth, laterally not protruding as far as ring 2 (Fig. 8AView Figure 8).

Body rings: ozopores starting at segment 6, marked by a black spot. Located slightly before, but touching suture between meso- and metazonite. Rings with smooth, but irregular coriaceous surface, ventrally on metazona with transverse ridges.

Telson: paraprocts without lips, abundant micropunctation especially towards edges (Fig. 8CView Figure 8). Epiproct well-rounded, covering, but not reaching above paraproct (Fig. 8CView Figure 8). Hypoproct inconspicuous (Fig. 8CView Figure 8).

Legs: leg 1 with a large cylindrical coxa, twice as long as other podomeres. Tarsus with three pairs of ventral spines and an apical spine beyond claw. Leg 2 with an elongated coxa and a strongly swollen prefemur. Tarsus with two pairs of ventral spines and a short apical spine. Midbody legs with a rectangular coxa, as long as other podomeres. Each podomere ventrally with a single or a pair of apical setae, tarsus with a tarsal pad, a single apical and two pairs of ventral spines. Length of midbody legs ca. 1.2 times body diameter in males.

Female: unknown.

Male sexual characters: tarsal pads absent (Fig. 8BView Figure 8). Coxae 3-7 without coxal processes (Fig. 8BView Figure 8).

Anterior gonopod sternite massive (Fig. 8DView Figure 8), elongated into a wide, well-rounded triangular lobe (Fig. 8DView Figure 8). Sternite in anterior view well-visible, without discernible apodemes, protruding almost as high as coxal processes. Coxite with sharp triangular mesal process (Fig. 8D, EView Figure 8). Telopodite with slender process arising mesally (Fig. 8EView Figure 8), process apically curved with a short triangular projection (Fig. 8DView Figure 8), tip well-rounded tip, slightly protruding above lateral margin of telopodite (Fig. 8EView Figure 8).

Posterior gonopods consisting of two parts, separated by an articulation (Fig. 8FView Figure 8): a long coxite and a slightly shorter telopodite, efferent duct discharging apically (Fig. 8F, GView Figure 8). Process of coxite and telopodite standing in same axis (Fig. 8FView Figure 8). Pair of posterior gonopods located parallel to each other, connected by a small, sclerotised and visible sternite (Fig. 8FView Figure 8). Basal part of coxite wide, mesally with a large triangular sclerite located on lower level than remaining part (Fig. 8FView Figure 8). Coxite elongated. Efferent duct running at mesal margin of coxite (Fig. 8F, GView Figure 8). Telopodite as wide as but slightly shorter than coxite, standing in same axis (Fig. 8F, GView Figure 8), apically membranous, with two slender apical processes resembling a bull’s horns (Fig. 8F, GView Figure 8). Mesal process wider and longer than lateral process. Efferent duct seems to be ending at base of mesal process (Fig. 8F, GView Figure 8).

Remarks.

Riotintobolus bovinus  sp. nov. lives in direct sympatry with another species of the genus, Riotintobolus makayi  sp. nov. (Fig. 2View Figure 2).