Zoosphaerium beanka Wesener & Sagorny 2021, sp. nov.

Zoosphaerium beanka sp. nov.

urn:lsid:zoobank.org:act: 7F9589AA-AD5D-473F-A7C1-FB94F30FF8AD

Figs 2D, 3, 5D, 8

Diagnosis

The shape and position of the locking carinae place Z. beanka sp. nov. in the Z. platylabum speciesgroup, but the telopods of Z. beanka sp. nov. have almost no similarities to those of any other described giant pill-millipede species except Z. tsingy. Both species share characters of the posterior telopods, namely the presence of spines and at least one large membranous lobe on the movable finger, and an uncurved, wide immovable finger (2.7 times as long as wide) that is parallel to the movable finger. Zoosphaerium beanka sp. nov. differs from the latter in the light brown color (olive in Z. tsingy), the presence of only four apical cones on the antenna (> 15 in Z. tsingy) and the differently shaped anterior telopods, in which telopoditomere 3 lacks crenulated teeth (present in Z. tsingy).

Etymology

‘Beanka’, noun in apposition, after the type and only known locality for this species, the dry forest of Beanka (Fig. 3).

Material examined

Holotype MADAGASCAR – Mahajanga • ♂; Forêt de Beanka; 18°01′25″ S, 44°30′08″ E; alt. 220 m; slightly disturbed dry deciduous forest; 14 Jan. 2010; Z.H. Harimpitia leg.; coll. no. Z.H.H-031; FMNH-INS 3119897.

Description

BODY LENGTH. Male (holotype): length 36.7 mm, width of thoracic shield up 22.1 mm (widest), height of thoracic shield 11.8 mm (highest).

COLORATION. Head, collum, thoracic shield, tergites and anal shield light brown (Fig. 2D). Antennae green, legs light brown.

HEAD. Eyes with more than 75 ommatidia. Antennae short, protruding back to leg 3. Length of antennomeres 1>2=3 =4=5 <6. A shallow groove present on antennomere 1, disc with 4 apical cones.

GNATHOCHILARIUM AND MANDIBLE. Not dissected.

STIGMATIC PLATES. First stigmatic plate triangular, apex well rounded, nearly as wide as at base, slightly turned towards coxa. Hairs most abundant on apical margin, very few hairs on basal and lateral margins (Fig. 8C).

PLEURITES. First pleurite slightly extending posteriorly in a well-rounded process.

COLLUM. Margins covered with a few short hairs, central part glabrous.

THORACIC SHIELD. Surface like those of tergites, glabrous.

TERGITES. Smooth and glabrous, no small pits present. Paratergites projecting slightly posteriorly.

ENDOTERGUM. Inner section with numerous short spines and isolated bristles. Between marginal ridge and inner area, a single row of sparse large, circular cuticular impressions. Externally one or two rows of marginal bristles, standing irregularly to each other. Bristles scaly, of medium length, longest reaching slightly above tergite margin (Fig. 5D).

ANAL SHIELD. Rounded, neither bell-shaped nor tapered, glabrous. Ventral side of anal shield with two black locking carinae, located close to laterotergites. Anterior carina small, posterior carina 2–3 times as long as anterior carina.

LEGS. Leg 1 with 6 or 7 ventral spines, leg 2 with 8, leg 3 with 10. First two leg pairs without an apical spine, spine present on leg 3. Leg pairs 4–21 with 9 or 10 ventral spines and an apical spine. On leg 9, femur 2 and tarsus 4.9 times as long as wide. All podomeres with setae (Fig. 8A).

Male sexual characters

GONOPORE. Covered with a single undivided, rounded membranous plate, covering ¼ of surface of coxa. Gonopore located centrally on joint (Fig. 8B).

ANTERIOR TELOPODS. Harp with two stridulation ribs, mesal rib smaller than lateral one, both ribs well developed (Fig. 8F). First podomere 1.2 times as wide as long. Second podomere process lobe-like and slightly curved, with rounded edges, protruding up to half of third podomere height, apically with sclerotized spots. Third podomere long, as long as first; cavity mesally with numerous sclerotized spots and three thin, sclerotized spines; one sclerotized spot located close to tip. Podomeres 1–3 covered on both sides with numerous long, isolated hairs.

POSTERIOR TELOPODS. Movable finger with a well-rounded tip, not tapering towards tip; hollowed-out inner margin with one non-sclerotized lobe and 3 or 4 sclerotized spines, posterior aspect with ca 14 small sclerotized teeth. Movable finger slightly longer than fixed finger, the latter straight, as wide as third podomere. Fixed finger at margin with numerous sclerotized spots. All podomeres covered on both sides with numerous, long isolated hairs, only tips of chela glabrous (Fig. 8G–H).

Female

Unknown.

Distribution and ecology

Zoosphaerium beanka sp. nov. is currently known only from the dry forest of Beanka (Fig. 3). With most known dry forest giant pill-millipede species being widespread (Wesener & Wägele 2008; Wesener 2009), this species can be expected in surrounding dry forest fragments.