Thiratoscirtus bipaniculus

Thiratoscirtus bipaniculus is a medium-sized spider with unique physical features. The spider's body is divided into two main parts: the cephalothorax, which is ovoid, and the abdomen, which is a long and thin oval.^[11] Females of this species have a cephalothorax measuring typically 2.6 mm (0.10 in) in length and 2 mm (0.08 in) in width. The carapace, the hard upper part of the cephalothorax, is high with a sharp slope to the rear. It is generally dark brown and covered in brown hairs. There is a depression in the centre of the carapace, or fovea that is lighter. The spider's eye field has colourless hairs with longer brown bristles near the eyes themselves. The eyes are also surrounded in black rings. The sides of the carapace have bands of white hairs. The underside of the cephalothorax, or sternum, is orange.^[10]

The spider's face, known as the clypeus, is very low. The mouthparts include strongly-built dark brown chelicerae, with teeth that have multiple points and a short fang and a light brown labium. Its abdomen is typically 2.5 mm (0.10 in) in length and 1.9 mm (0.07 in) in width. The upper part is dark grey with delicate short hairs and an indistinct pattern combining lines and chevrons. The lower part is yellowish-grey. There are long brown bristles on the front edge. The spider's spinnerets are light grey. Its legs are light brown, with spines being present on the front pair. The pedipalps, sensory organs near the mouth, are brown with a pronounced spine.^[10]

The spider has distinctive copulatory organs. Its epigyne is elongated and has a rectangular trough to the front, slightly sclerotized structures in the middle and a v-shaped edge to the very back. The sclerotized structures are characteristic of the species but it also has clumps of very long dense hairs along the sides that are most distinctive for this spider and help distinguish it from others in the genus.^[10] The only related spider that shares this characteristic is Thiratoscirtus kalisia, which has an additional T-shaped depression to the back of the epigyne and wide insemination ducts.^[2] Thiratoscirtus bipaniculus has two copulatory openings that lead to long thin insemination ducts and sphericalspermathecae, or receptacles.^[10] The male has not been described.^[1]

Thiratoscirtus spiders generally live in Africa and are particularly common in the forests of Central and West Africa.^[2] Thiratoscirtus bipaniculus is endemic to Nigeria.^[1] The holotype was found on Obudu Plateau, Cross River State, in 1974 at an altitude of 1,900 m (6,200 ft) above sea level.^[10]