Metabiantes kaurii sp. nov.

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

Figs 21–24; 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, 22A, 23B, D, F). 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 vs Fig. 17C–D). 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 vs Fig. 18B) and the presence of lateral projections in M. kivuensis (Fig. 24B vs Fig. 29B). 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 vs Fig. 18B, D). 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, 22A vs Figs 25A, 31A). Furthermore, the male of M. kaurii lacks an enlarged trochanter II, distinguishing it from those of M. pusulosus (Fig. 21A 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 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 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 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.

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, 22A). Carapace granulated, wider than long, anterior border convex, and unarmed (Figs 21A, 22A). Cheliceral sockets not marked (Fig. 22E). Eyes separated near sulcus I; interocular area granulated (Figs 21E, 22A). Carapace in lateral view straight in anterior region and slightly higher posteriorly (Fig. 21E). Abdominal scutum in lateral view convex (Fig. 21E). Sulcus I deep and complete, curving slightly posteriorly at midline in dorsal view (Fig. 22A). 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, 22A). Lateral margins of abdominal scutum with two rows of granules (Fig. 22A). Free tergites with two rows of granules (Figs 21E–F, 22A).

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

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

PEDIPALP. Coxa elongated (i.e., remarkably longer than trochanter), dorsoproximally with one mesal and one ectal granule (Figs 21A, 22A). Trochanter unarmed. Femur straight, proximally with one small ventromesal spine (Fig. 22B–D). Patella elongated, club-shaped, and armed with a small distal ventromesal spine (Fig. 22B). Tibia with two ventromesal and two ventroectal spines, with distal ventroectal spine longest (Fig. 22B–C). 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).

LEGS. Femur II unarmed, proximally thin, followed by an abrupt strong thickness, then tapering gradually (Fig. 23A–B). Patella II short and unarmed. Tibia II widened and unarmed (Fig. 23C–D). Metatarsus III with astragalus occupying the half region (Fig. 23E–G), ventrally with triangular-shaped tubercles (Fig. 23F–I). Calcaneus occupies half of metatarsus, with scattered low and rounded trichomes and long sensilla chaetica along the lateral surface (Fig. 23H–J). 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); carapace with brown reticulations on anterior and lateral regions (Fig. 21A). Lateroanterior, lateral, and lateroposterior borders of mesotergal areas I–III and anal operculum dark brown (Fig. 21A, F); lateroanterior, lateral, and posterior borders of mesotergal area IV with dark brown patches (Fig. 21A). Mesotergal area V and free tergites with two lateral dark brown patches (Fig. 21A); coxae I–IV with brown reticulations; free sternites with anterior dark brown patches (Fig. 21B, D). Appendages with brown reticulations or dark patches (Fig. 21A–B, E).

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). Pars basalis tubular, basally thin, gradually widening toward distal region (Fig. 24A); pars distalis slightly swollen, with maximum width at titillator level (Fig. 24B), and ventrally with slight angular lateral edges (Fig. 24D). 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). Pars distalis with a small distal depression in the ventromedial region (Fig. 24D). Each side of pars distalis bearing small conical microsetae irregularly arranged, extending from the dorsal to ventroapical region (Fig. 24B–D). 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). 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), with a rounded tip (Fig. 24B, D).

Female

Unknown.

Distribution

Known only from the type locality (Fig. 40).