Sitamacho Wood & Kulkarni & Ramírez & Scharff 2024, gen. nov.
Creators: name: Wood, Hannah M.
name: Kulkarni, Siddharth
name: Ramírez, Martín J.
name: Scharff, Nikolaj
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Palpimanidae
Sitamacho

description: Genus Sitamacho gen. nov.
Type species: Sitamacho tao sp. nov.
Etymology: The name ‘sita’ is Swahili for six, and ‘macho’ is Swahili for ‘eyes’, for the six eyes found in these spiders; the gender is feminine.
Diagnosis: Distinguished from all other palpimanids except Hybosida by having six eyes, with the posterior median eyes (PME) absent or vestigial. Distinguished from Hybosida by the unique shape of the fovea, appearing like a wide, inverted ‘u’ in dorsal view, and consisting of two slits/seams that diverge posteriorly (Fig. 6D, G).
Description: Body ~ 2 mm long. Carapace, sternum, and chelicerae reddish brown. Carapace with fine tubercles, with scale texture on the lateral and posterior surfaces, with small setae that are longer around the eyes. Carapace domed, highest in middle, then steeply sloping down. Clypeus tall, approximately three times AME diameter. Chelicerae with patch of fine stridulatory ridges, with peg teeth present. Sternum, with scale texture, fused with intercoxal sclerites. Labium triangular, with a deep notch. Subcheliceral sclerite fused with carapace, forming foramen around cheliceral bases. Fovea bipartite, consisting of two slits that diverge posteriorly. AME approximately two times larger than LE. LE contiguous. PME absent or rudimentary. Legs, ordered by size from largest to smallest 1423, light reddish brown, without spines, with a thick brush of thickened setae on distal, ventral edge of metatarsi II–IV. Leg I most robust, with enlarged femora, and with patella about twice as long as femora. Tarsi with two superior claws with teeth, and light claw tufts present. Abdomen pale yellow, uniformly scattered with light brown setae. Sclerotization encircling anterior portion of abdomen, extending to epigastric furrow. Light sclerotization around tracheal spiracle opening. ALS present; PMS and PLS absent. Female genitalia known only in Sitamacho tao, described below. Male pedipalpal bulbs with a small conductor, an embolus that is mostly hidden within the bulb until expansion, and a median apophysis. Female pedipalps with prolateral brush of hairs and with thickened tibia and tarsus.
Included species: Three described species, here transferred from Hybosida as new combinations: Sitamacho lesserti (Berland, 1920), Sitamacho machondogo (Oketch & Li, 2020), and Sitamacho scabra (Simon & Fage, 1922), plus Sitamacho tao sp. nov. and two undescribed species included in our phylogeny.
Distribution: East Africa.
Discussion: The undescribed Sitamacho species and Sitamacho tao are morphologically similar to the described species, here transferred from Hybosida. These species share the uniquely shaped fovea, have no PME, and have a common configuration of the male palp (compare Figs 6A–F with 7A, B, D, E).
description: Published as part of Wood, Hannah M., Kulkarni, Siddharth, Ramírez, Martín J. & Scharff, Nikolaj, 2024, Phylogeny and biogeography support ancient vicariance and subsequent dispersal out of Africa in Palpimanidae spiders (Araneae), pp. 1-26 in Zoological Journal of the Linnean Society 202 (2) on page 22, DOI: 10.1093/zoolinnean/zlae129, http://zenodo.org/record/14714442