Sphaerobelum spinatum Wesener 2019, new species
Creators: name: Wesener, Thomas
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Diplopoda
Sphaerotheriida
Zephronidae
Sphaerobelum
Sphaerobelum spinatum

description: Sphaerobelum spinatum new species
Figures 6D, 9C, 14, 15, 16
Material examined: Type specimens. 1 M holotype (ZMUC00040258) from Laos, Vientiane Province, Phou Khao Khouay (N18°20.369' N, 102°48.523'E), 700–800 m, strongly disturbed primary evergreen forest, leg. 26- 31.V.2008, A. Solodovnikov & J. Pedersen; 1 F paratype; ZMUC00040259; same data as paratype; 1 M, 1 F paratype (ZFMK MYR8101 & MYR8102), same data as holotype.
Diagnosis: S. spinatum n. sp. belongs to a group of Sphaerobelum species in which the mesal margin of the femur is extended with several teeth (Fig. 15B). S. spinatum n. sp. shares only with S. cattiense and S. konkakinhense a straight telopoditomere 4 (Figs 16E, F). S. spinatum n. sp. differs in several characters from both other species: mesal margin of prefemur with indentations like the femur (Fig. 15B), male antenna with <60 apical cones (> 70 in S. denticulatum n. sp.), tergites shiny, but setose (tergites covered with setose pits in the other species), first laterotergite strongly projecting, extended into a sharp tip (first laterotergite only weakly projecting in the other two species).
Description. Based on holotype and both paratypes.
Measurements: Body length: holotype male: length ca 26.9 mm. Width, of thoracic shield = 13.6 mm (= broadest). Height, of thoracic shield = 7.5 mm (= highest). Female: length ca 32.5 mm. Width, of thoracic shield = 14.5 mm, of tergite 7 = 15.7 mm (=broadest). Height, of thoracic shield = 7.7 mm, of tergite 9 = 9.1mm (= highest).
Coloration: in preserved specimens black, paratergite depressions and groove of thoracic shield dark green (Fig. 6D). Antennae brown-orange, legs light brown, but prefemur and femur green.
Head: Eyes with>60 ocelli. Aberrant ocellus located inside antennal groove. Antennae short, with rounded joints, extending posteriorly to leg-pair 5. Lengths of antennomeres: 1>2=3=4=5<<6 (Fig. 14A). All antennomeres densely pubescent, sensilla basiconica surrounding apical disc. Shape of antennae sexually dimorphic, cylindrical in female, thickened, apically widened and slightly flattened in male (Fig. 14B). Apical disc with ca 52/52 apical cones (male) (Fig. 14b), or 30–36 (female). Organ of Tömösváry located inside antennal groove. Gnathochilarium: Damaged. Structure typical of the order (Fig. 14C). Palpi with sensory cones arranged in single field. Rudimentary lateral palps not visible.
Mandibles: not dissected.
Stigmatic plates: first stigmatic plate rounded, apex well-rounded, straight towards coxa 1 (Fig. 15A). Laterotergites: laterotergite 1 strongly projecting into a sharp tip. Laterotergite 2 with a broad, stout, much shorter projection. Collum: with glabrous surface, margins with few isolated setae. Thoracic shield: surface glabrous but covered with tiny pits, setae only in grooves. Slope towards groove without anterior keels but with 4 or 5 posterior keels. Tergites: surface anterior half densely setose with short setae, posterior half glabrous, shiny. Tips of paratergites of midbody tergites projecting posteriorly (Fig. 6D). Endotergum: inner section lacking any spines or setae. Middle area with a single row of large, sparse, elliptical, cuticular impressions. Distance between impressions twice as wide as their diameter. Apically, 2-3 dense rows of long marginal bristles, the tips of the longest setae slightly protruding beyond tergal margin (Fig. 9C). Bristles not smooth, but with numerous small spinicles. Anal shield: large, in both sexes well-rounded. Surface in both sexes completely covered by tiny setae located in small pits. Underside with a single, short, black, locking carina, located close to last laterotergite. Legs: leg-pair 1 with 2 or 3 ventral spines, leg-pair 2 with 6, leg-pair 3 with 7 or 8. First two leg-pairs without an apical spine. Leg-pairs 4–21 with 10 ventral spines and one dorso-apical spine. In leg 9, femur 1.6 times, tarsus 3.7 times longer than wide (Fig. 15B). All podomeres densely setose. Coxa with a large and marginally toothed process. Coxa process absent at first leg (Fig. 15A) and sharply projecting at second (Figs 15C, 16A). Prefemur at apical margin with a projection laterally and mesally. Lateral projection triangular and sharply edged, juxtaposed to coxal process. Femur extended mesally into a dentate margin featuring 12–14 teeth.
Female sexual characters: female gravid. Vulva large, covering 2/3 of coxa, extending mesally to anterior third of prefemur (Fig. 15C). Operculum rounded, very slightly invaginated medially, mesal margin strongly projecting into a well-rounded lobe twice as high as remaining operculum. Subanal plate: large and wide, divided by a suture into two halves. Densely setose (Fig. 15D).
Male sexual characters: gonopore covered with a single, undivided, circular, sclerotized plate (Fig. 16A). Anterior telopods (Figs 16 B–D): consisting of 4 telopoditomeres above syncoxite. Telopoditomere 1 rectangular, as long as wide. Telopoditomere 2 large, as long as telopoditomere 1. Process of telopoditomere 2 located posteriorly, not visible in anterior view. Process of telopoditomere 2 wide, well-rounded, projecting to half of telopoditomere 3. Telopoditomere 3 small, slightly shorter than telopoditomere 4. telopoditomere 4 cylindrical, well-rounded, posterior side with two small spines. All telopoditomeres covered with long setae. Posterior telopods (Figs 16E, F): telopoditomere 1 short, half as long as wide. Immovable finger (process of telopoditomere 2) as long as movable finger, consisting of telopoditomeres 3 and 4. Immovable finger with a characteristic, distally swollen apex, well rounded apically, apex only slightly wider than base. Telopoditomere 3 rectangular, well rounded, apically with a well-rounded extension carrying a small spine. Telopoditomere 4 only slightly shorter and slightly more slender than telopoditomere 3, 2.1 times longer than wide, apically weakly tapering, straight, not curved, with 3 small spines at margin towards immovable finger. In anterior view telopoditomere 1–3 covered by setae, in posterior view telopoditomeres 2–4 mostly glabrous except for a few setae at the margins.
Derivatio nominis: spinatum, noun in apposition, after the sharp process of the first laterotergite.
description: Published as part of Wesener, Thomas, 2019, First records of giant pill-millipedes from Laos (Diplopoda, Sphaerotheriida, Zephroniidae), pp. 201-248 in Zootaxa 4563 (2) on pages 221-224, DOI: 10.11646/zootaxa.4563.2.1, http://zenodo.org/record/2601072