Martensiellus

Schwendinger, Peter J., 2006, A taxonomic revision of the family Oncopodidae VI. Martensiellus, a new genus from Borneo, and the discovery of a tarsal pore organ in Oncopodidae (Opiliones: Laniatores), Zootaxa 1325, pp. 255-266 : 258

Martensiellus n. g.

Type species. Martensiellus tenuipalpus n. sp.

Etymology. The generic name (male in gender) is derived from the name “Martens”.

Diagnosis. The new genus is characterized by the following combination of characters: 1. The penis carries an expandable, distad­directed glans in which the median plate lies dorsally of the lateral sclerites ( Figs 11–17 ). The same is found in Biantoncopus Martens & Schwendinger , whereas in the distad­directed glans of Palaeoncopus Martens & Schwendinger the plate lies ventral to the sclerites. 2. A dorsal pore is present on tarsi of legs I and II, as is also the case in Palaeoncopus and Caenoncopus . In Oncopus dorsal pores are present on all leg tarsi. In Gnomulus Thorell and Biantoncopus tarsal pores are absent. 3. The tarsal formula is 1­1­2­2 (as in Caenoncopus cuspidatus ), all tarsi/ tarsomeres are large. In lateral view the undivided tarsi of legs I and II in Martensiellus n. g. are ovoid, clearly longer than deep ( Figs 6–7 ), whereas in Caenoncopus they both are semiglobular and clearly deeper than long (see Martens & Schwendinger 1998: fig. 4c). In Oncopus (see Thorell 1891: figs 34–35) and, less distinctly so, in Palaeoncopus the tarsus of leg I is slightly longer than deep and the tarsus of leg II slightly deeper than long. Tarsomeres of legs III and IV in Martensiellus n. g. are fairly long and large, only slightly less deep than the corresponding metatarsi in their proximal portion ( Figs 8–9 ). This is also the case in Gnomulus (see Silhavy 1962: fig. 4) and Biantoncopus (see Martens & Schwendinger 1998: fig. 69), whereas in Caenoncopus (see Martens & Schwendinger 1998: figs 4b, d) and Palaeoncopus the tarsomeres of legs III and IV are short and small, only about half as deep as the corresponding metatarsi.

Species account and distribution. At the moment only one species from central Sarawak can be unequivocally attributed to the new genus. Females of two different species from eastern Sarawak and southern Kalimantan (see paragraph “ Martensiellus n. g. spp. ”) presumably also belong there, but generic placement without males is uncertain. Several more species of this new genus are expected to occur in different parts of Borneo.

Figures

FIGURES 11 – 17. Martensiellus tenuipalpus n. g., n. sp., penis (11 – 14 holotype, 15 – 17 paratype). 11 – 12. Total penis (11 dorsal view, 12 lateral view). 13 – 15, 17. Apex of penis in resting position (13, 15 dorsal view, 14, 17 lateral view). 16. Apex of penis with expanded glans, dorsal view. Abbreviations: d. m. distal margin of truncus penis, l. s. lateral sclerite of glans, m. p. median plate of glans, m. t. membranous tubes of glans, s stylus. Scale bars: 0.5 mm (11 – 12), 0.1 mm (13 – 17).

FIGURES 4 – 10. Martensiellus tenuipalpus n. g., n. sp., male (4 – 9 holotype, 10 paratype). 4. Chelicera, lateral view. 5. Palpus, lateral view. 6. Distal parts of legs, lateral view (6 leg I, 7 leg II, 8 leg III, 9 leg IV). 10. Palpus and anterior part of body, lateral view. Scale bars: 1 mm (4 – 9 same scale).