Geotypodon millemanus gen. et sp. nov.

urn:lsid:zoobank.org:act: D65889F9-1063-4FBB-AEBB-A594052220B1

Figs 1–4

Diagnosis

A species of Geotypodon gen. nov. in which the gonopod coxal metaplica is produced mesad in a thin lamella, a small longitudinal lamella, perpendicular to the other, is present on the anterior part of the metaplica, the telomere is apically divided into two lobes of approximately equal size, and the limbus lobes are multi-cusped, hand-like. It shares these characters with G. submontanus gen. et sp. nov., but differs from that species in larger size, straight mesal margin of metaplical lamella and absence of a spine-like process on the posterior apical telomeral lobe.

Etymology

The name is a Latin noun in apposition, meaning “a thousand hands” and referring to the hand-like limbus lobes. A specimen with a diameter of 5 mm will have a body perimeter of approximately 15 mm. Assuming that the limbus covers only 10 mm, and taking into account that each “hand” occupies about 10 microns of the perimeter, each body ring will carry about a thousand “hands”, and a specimen with 60 body rings will therefore have roughly 60,000 “hands”.

Material studied (total: 4 ♂♂)

Holotype

TANZANIA: ♂, Iringa Region, Iringa District, Udzungwa Mts, West Kilombero Scarp FR, 07°50'38.4"S, 36°22'17.6" E, montane forest, 1390–1410 m asl, Plot Paradiso, casual, 18 Nov. 2000, Frontier Tanzania leg. ( ZMUC00040350).

Paratypes

TANZANIA: 2 ♂♂, same data as holotype (ZMUC100969, ZMUC00040345); 1 ♂, Iringa Region, Iringa District, Udzungwa Mts, Kiranzi-Kitungulu FR, 08°09' S, 35°05' E, forest, 1500 m asl, Jan. 1996, M. Andersen, P. Gravlund & A. Jakobsen leg. (ZMUC00046991).

published measurements for other Geotypodon species.

Type locality

TANZANIA, Iringa Region, Iringa District, Udzungwa Mts, West Kilombero Scarp FR, 07°50'38.4" S, 36°22'17.6" E, montane forest, 1390–1410 m asl, cf. Marshall et al. (2001).

Description

SIZE. Length ca. 9 cm. Diameter 4.8–5.1 mm. 60–66 podous rings, no apodous rings in front of telson.

COLOUR. After 15 years in alcohol somewhat faded, but pattern still evident. Upper part of head blackish, lower part yellowish. Overall colour of body ventrally and laterally yellowish. Posterior ca. 40% of metazona amber, in front of amber zone a blackish zone; blackish zone narrow laterally, becoming wider dorsally where extending onto posterior 1/4–1/3 of prozona; resulting mid-dorsal dark band becoming narrower towards head. Telson blackish with yellowish margins, legs yellowish.

HEAD. Without peculiarities.

COLLUM. With a marginal and a submarginal furrow.

BODY RINGS. Almost perfect cylinders, not vaulted; suture straight; ozopores ca. three diameters behind suture.

LIMBUS ( Fig. 4). Consisting of isolated hand-like lobes of ca. 10 microns’ length, each with 3–6 ‘fingers’ and each with a ridge running along its length.

ANAL VALVES. Each with a well-developed dorsal spine and a smaller, yet distinctive ventral one; margin raised, with 3 setae not borne on tubercles.

MALE LEGS. From 5 th pair with postfemoral and tibial pads on all legs, except last four pairs; tibial pads absent from several pairs in front of these.

GONOPOD COXA ( Fig. 4). Slender, slightly sigmoid. Proplica ( pp) ending in small proplical lobe hidden behind anterior edge of metaplical lamella ( mla), on Fig. 4B. Metaplica ( mp) with poorly developed basal anteriad flange ( mf), disto-mesally expanded into thin lamella ( mla), with a straight mesal margin, tip of metaplica formed by blunt-triangular extension of mla; a second smaller longitudinal lamella ( ll) on anterior surface of metaplica partly covering proplical lobe; metaplica at level of proplical lobe, with a long, slightly curved spine-like process ( msp) directed toward base of coxa on its anterior side.

GONOPOD TELOPODITE ( Fig. 4). Arculus 90°. Torsotope ( tt) simple, compact, without processes ( Fig. 4B). Posttorsal narrowing ( pn) pronounced, very slender, without processes or spines ( Fig. 4B). Telopodite just distal to posttorsal narrowing dividing into slender, whip-like solenomere and complicated telomere. Solenomere ( slm) curved in 3 dimensions (at least on preserved specimens), apically pointed, without any outgrowths ( Fig. 4A, C, E). Efferent groove continuing from posttorsal narrowing onto solenomere and running all the way to its tip. Telomere with long, stout basal spine ( pts), spine first curving in parallel with solenomere, but then becoming straight and directed mesad ( Fig. 4A, C). Telomere close to pts with a basal lamella ( bl) ( Fig. 4A), followed by several complicated lamellar parts; basal part of telomere partly sheathing base of solenomere, distal part divided into two equally-sized thin lobes ( atl and ptl), which initially diverge at ca. 90° but then curve towards each other ( Fig. 4B, D–E). An intermediate lamella ( itl) lodged in the space between atl and plm ( Fig. 4D). Surfaces of atl and ptl facing each other, concave, margins of each lobe subparallel, smooth; telomere entirely without denticles or spines.

Distribution and habitat

Known from West Kilombero FR and Kiranza-Kitungulu FR. Altitudinal range: 1145–1500 m asl. Haibtat: (montane) forest.

Coexisting species

In Kiranza-Kitungulu FR G. millemanus gen. et sp. nov. was found in the same sample as Chaleponcus dabagaensis Kraus, 1958 and C. gracilior Enghoff, 2014. In West Kilombero FR no other odontopygids were found in the same sample as G. millemanus gen. et sp. nov., but G. submontanus gen. et sp. nov., Chaleponcus basiliscus Enghoff, 2014, C. circumvallatus Enghoff, 2014, C. gracilior, C. ibis Enghoff, 2014, C. netus Enghoff, 2014, C. tintin Enghoff, 2015, Aquattuor longipala Enghoff 2015 and A. udzungwensis Enghoff, 2015 also occur in West Kilombero FR.