Metabiantes kaurii, Mamani & Jocqué & Pérez-González, 2025

Mamani, Vanesa, Jocqué, Merlijn & Pérez-González, Abel, 2025, Notes on African Biantinae with sexual dimorphism in leg II: five new Metabiantes species and redescription of Clinobiantes paradoxus (Opiliones: Laniatores: Biantidae), European Journal of Taxonomy 1006, pp. 1-58 : 29-33

publication ID	https://doi.org/10.5852/ejt.2025.1006.2989
publication LSID	lsid:zoobank.org:pub:E4FAF05B-5420-42B0-AB8D-5870FD3E370A
persistent identifier	https://treatment.plazi.org/id/03C2879B-FFF2-FF92-4437-A15960D1F43A
treatment provided by	Plazi
scientific name	Metabiantes kaurii
status	sp. nov.

Treatment

Metabiantes kaurii sp. nov.

urn:lsid:zoobank.org:act:44F823B9-361E-4C7C-B792-D685D7DEC49F

Figs 21–24 View Fig View Fig View Fig View Fig ; Table 4

Diagnosis

Metabiantes kaurii sp. nov. differs from its congeners (except M. herculeus sp. nov., M. kivuensis sp. nov., M. machadoi , M. obscurus , M. pusulosus , and M. zuurbergianus ) by the following combination of traits: absence of tubercles on mesotergal areas III–V and free tergites; sexually dimorphic male leg II with a thickened femur, a broad tibia, and a metatarsus ventrally armed with tubercles ( Figs 21A View Fig , 22A View Fig , 23B, D, F View Fig ). Male of M. kaurii differs from M. herculeus by the absence of ventral tubercles on tibia II, present in the latter species ( Fig. 23C–D View Fig vs Fig. 17C–D View Fig ). The penis of M. kaurii is distinctive with widely separated conductors and lacking lateral projections, unlike the close-together conductors in M. herculeus ( Fig. 24B View Fig vs Fig. 18B View Fig ) and the presence of lateral projections in M. kivuensis ( Fig. 24B View Fig vs Fig. 29B View Fig ). Additionally, the longer, contacting halves of the lamina apicalis in M. kaurii contrast with the shorter, non-contacting halves in M. herculeus ( Fig. 24B, D View Fig vs Fig. 18B, D View Fig ). Unlike M. kivuensis , M. kaurii lacks a longitudinal division of mesotergal area IV into two halves, which is characteristic of females and major males of M. kivuensis ( Figs 21A View Fig , 22A View Fig vs Figs 25A View Fig , 31A View Fig ). Furthermore, the male of M. kaurii lacks an enlarged trochanter II, distinguishing it from those of M. pusulosus ( Fig. 21A View Fig vs Kauri 1961: fig. 5a). Also, the male of M. kaurii is distinguished from that of M. machadoi by its abruptly thickened femur II ( Fig. 23A View Fig vs Lawrence 1957: fig. 3b). The penis of M. kaurii features a deeper U-shaped cleft of the lamina apicalis, wider titillators, and smaller basal setae, which distinguish it from the shallow cleft, narrow titillators, and larger basal setae in M. obscurus and M. zuurbergianus ( Fig. 24B–D View Fig vs Kauri 1961: figs 7a–b, 11a–b). Additionally, the slight triangular lateral edges of the pars distalis and wide titillators in M. kaurii differ from the stronger triangular lateral edges of the pars distalis and narrow titillators in M. pusulosus ( Fig. 24B–D View Fig vs Kauri 1961: fig. 1a–b).

Etymology

The species epithet is a patronym, honoring the Estonian arachnologist Hans Kauri (1906–1999) for his contributions to opilionology, particularly that of the African fauna.

Type material

Holotype

MOZAMBIQUE • ♂; Niassa; 12.38278° S, 35.33369° E; 1724 m a.s.l.; 14 Nov. 2006; L. Geeraert and M. Jocqué leg.; montane forest; pitfall trap; MACN-Ar 46476. GoogleMaps

Description

Male (holotype, MACN-Ar 46476)

BODY MEASUREMENTS. Total body length 2.41, carapace length 0.71, scutum magnum length 2.28, carapace maximum width 1.08, abdominal scutum maximum width 1.53. Appendage measurements in Table 4.

DORSUM. Outline hourglass-shaped with Eta (η) shape, with a slight constriction posteriorly at sulcus I level ( Figs 21A View Fig , 22A View Fig ). Carapace granulated, wider than long, anterior border convex, and unarmed ( Figs 21A View Fig , 22A View Fig ). Cheliceral sockets not marked ( Fig. 22E View Fig ). Eyes separated near sulcus I; interocular area granulated ( Figs 21E View Fig , 22A View Fig ). Carapace in lateral view straight in anterior region and slightly higher posteriorly ( Fig. 21E View Fig ). Abdominal scutum in lateral view convex ( Fig. 21E View Fig ). Sulcus I deep and complete, curving slightly posteriorly at midline in dorsal view ( Fig. 22A View Fig ). Mesotergal areas granulated and well-defined, with sulci II–V marked but shallower than sulcus I; sulci II–III slightly curved anteriorly; sulci IV–V straight. Mesotergal area V granulated ( Figs 21A View Fig , 22A View Fig ). Lateral margins of abdominal scutum with two rows of granules ( Fig. 22A View Fig ). Free tergites with two rows of granules ( Figs 21E–F View Fig , 22A View Fig ).

VENTER. Coxa I with some small setiferous granules; coxa II incrassated, of same size as (or slightly smaller than) coxa IV ( Fig. 21C View Fig ); anteroposterior borders of coxa III with a row of strong granules connecting with coxae II and IV, respectively ( Fig. 21C View Fig ). Posterior border of spiracular area, free sternites I–V with a row of granules ( Fig. 21D–F View Fig ); anal operculum granulated ( Fig. 21D–F View Fig ). Spiracles not concealed ( Fig. 21D View Fig ).

CHELICERA. Basichelicerite unarmed with a slightly marked bulla ( Fig. 22E View Fig ). Cheliceral hand with sparse setae ( Fig. 22E–F View Fig ). Fixed and movable fingers with small triangular-shaped teeth ( Fig. 22F View Fig ).

PEDIPALP. Coxa elongated (i.e., remarkably longer than trochanter), dorsoproximally with one mesal and one ectal granule ( Figs 21A View Fig , 22A View Fig ). Trochanter unarmed. Femur straight, proximally with one small ventromesal spine ( Fig. 22B–D View Fig ). Patella elongated, club-shaped, and armed with a small distal ventromesal spine ( Fig. 22B View Fig ). Tibia with two ventromesal and two ventroectal spines, with distal ventroectal spine longest ( Fig. 22B–C View Fig ). Tarsus inflated, of spheroid shape, armed with two ventromesal and two ventroectal spines; proximal spines longer than distal spines; ventroectal spine with the highest elevated socket; tarsus ventromedially with small granules ( Fig. 22B–C View Fig ).

LEGS. Femur II unarmed, proximally thin, followed by an abrupt strong thickness, then tapering gradually ( Fig. 23A–B View Fig ). Patella II short and unarmed. Tibia II widened and unarmed ( Fig. 23C–D View Fig ). Metatarsus III with astragalus occupying the half region ( Fig. 23E–G View Fig ), ventrally with triangular-shaped tubercles ( Fig. 23F–I View Fig ). Calcaneus occupies half of metatarsus, with scattered low and rounded trichomes and long sensilla chaetica along the lateral surface ( Fig. 23H–J View Fig ). Tarsi III–IV with a dense scopula. Tarsal formula: 3(2):5(4):5:5.

COLOR (specimen preserved in 80% ethanol). Body brown yellowish ( Fig. 21A–F View Fig ); carapace with brown reticulations on anterior and lateral regions ( Fig. 21A View Fig ). Lateroanterior, lateral, and lateroposterior borders of mesotergal areas I–III and anal operculum dark brown ( Fig. 21A, F View Fig ); lateroanterior, lateral, and posterior borders of mesotergal area IV with dark brown patches ( Fig. 21A View Fig ). Mesotergal area V and free tergites with two lateral dark brown patches ( Fig. 21A View Fig ); coxae I–IV with brown reticulations; free sternites with anterior dark brown patches ( Fig. 21B, D View Fig ). Appendages with brown reticulations or dark patches ( Fig. 21A–B, E View Fig ).

MALE GENITALIA. Pars basalis and pars distalis with indistinct boundaries, defined by the start of the most basal macrosetae marking the beginning of pars distalis ( Fig. 24A–D View Fig ). Pars basalis tubular, basally thin, gradually widening toward distal region ( Fig. 24A View Fig ); pars distalis slightly swollen, with maximum width at titillator level ( Fig. 24B View Fig ), and ventrally with slight angular lateral edges ( Fig. 24D View Fig ). Apical edge laminar (i.e., dorsoventrally flat) with a deep medial U-shaped cleft dividing it into two elongated, rounded halves, apically in contact ( Fig. 24A–B, D View Fig ). Pars distalis with a small distal depression in the ventromedial region ( Fig. 24D View Fig ). Each side of pars distalis bearing small conical microsetae irregularly arranged, extending from the dorsal to ventroapical region ( Fig. 24B–D View Fig ). Capsula externa with two broad titillators covering most of the capsula interna; titillators separated by a U-shaped cleft at the base, narrowing apically ( Fig. 24B–C View Fig ). Capsula interna formed by two laminar conductors and one stylus basally fused. Conductors apically curved toward medial region; conductor tips ventrally visible within U-shaped cleft. Stylus tubular, basally wide, apically thin, and with an irregular S-shaped curve in lateral view ( Fig. 24C View Fig ), with a rounded tip ( Fig. 24B, D View Fig ).