Loxosceles defecta Wunderlich, 1988

Magalhaes, Ivan L. F., Perez-Gonzalez, Abel, Labarque, Facundo M., Carboni, Martin, Hammel, Joerg U., Kunz, Robin, Ramirez, Martin J. & Solorzano-Kraemer, Monica M., 2022, Revision of recluse spiders (Araneae: Sicariidae: Loxosceles) preserved in Dominican amber and a total-evidence phylogeny of Scytodoidea reveal the first fossil Drymusidae, Arthropod Systematics & amp; Phylogeny 80, pp. 541-559 : 541

5.1.1. Loxosceles defecta Wunderlich, 1988

Fig. 1

Loxosceles defecta Wunderlich, 1988: 69, figs 92-94.

Type material.

Adult male holotype and adult male paratype in the same Dominican amber piece, holotype SMF Be 970a, paratype SMF Be 970b, deposited in SMF, examined. No other specimens are known.

Preservation.

Both spiders are preserved in the same reddish yellow amber piece. Both individuals are partly incomplete and preserved in moderate condition. In both spiders the abdomen is severely shrunk. The holotype has both palps (right palp slightly deformed, with a bubble trapped in the tibia), while the paratype has none. The holotype is missing right leg I, right leg IV and parts of right legs II and III; left leg I is detached from the body and preserved to the left of the animal. The paratype has all the legs on the right side but they are distinctly deformed and covered by emulsion; only part of femur IV remains in the left side. Syninclusions: a large leg of an entelegyne spider, a leaf, and a Collembola .

Diagnosis.

Loxosceles defecta can be diagnosed from the other Loxosceles in Dominican amber ( L. deformis ), as well as from extant Antillean species, by the sinuous, distally incrassate first tibia bearing macrosetae (Fig. 1E, F ); the palp has a gently curved, flattened embolus that is ~1.5 times as long as the globose base of the bulb and is less flattened than that of L. deformis .

Description.

Male holotype (SMF-Be 970a). Structure: Carapace slightly wider than long, narrowed anteriorly, particularly hirsute in the cephalic region, with a well-developed fovea. Leg I with sinuous tibia, distally incrassate, with ~5 visible macrosetae in the retrolateral face of the incrassate portion (Fig. 1E ); third claw absent. Palps (Fig. 1H, I ); femur elongate; tibia slightly incrassate, ventrally bulging; cymbium short and blunt, prolaterally bulging; bulb with small globose base and gently curved, flattened, slightly sinuous embolus. Measurements [mm]: Total length not possible to measure. Carapace length 1.98, width 2.02. Abdomen damaged. Palpal femur length 1.13. Palpal tibia length 0.70, height 0.35. Leg I: femur 3.08, patella 0.74, tibia 4.44, metatarsus and tarsus not possible to measure. Leg II: femur 3.37, patella 0.79, tibia 4.40, not possible to measure from metatarsus. Leg III: femur 2.23, not possible to measure from patella. Leg IV: femur 6.34, patella 1.64, tibia 3.76, metatarsus and tarsus damaged. - Male paratype (SMF-Be 970b). Structure: Six eyes in three dyads separated by 1-2 eye diameters (Fig. 2C ). Chelicerae with stridulatory files formed by deep ridges (Fig. 2D ), bifid cheliceral lamina and large promarginal lobe; teeth absent. Tibia I deformed, distally incrassate bearing macrosetae.

Figures

Figure 1. Loxosceles defecta Wunderlich, 1988, holotype (SMF-Be 970 a; A, B, E, G-I) and paratype (SMF-Be 970 b; C, D, F) embedded in the same amber piece, photographs under light microscopy. A habitus, dorsal view. Arrow to incrassate tibia I. B prosoma, dorsal view. C prosoma, subanterior view. Note six eyes in three dyads. D left chelicera, subanterior view. Arrows to bifid apex of cheliceral lamina. E left tibia I, retrolateral view. Arrow to incrassate region with strong macrosetae. F right tibia I, dorsal view. Arrow to strong macrosetae. G left tarsus I, apical view. Note absence of third claw. H right palp, retrolateral. I: left bulb, dorsal. Arrow to prolateral lobe of the cymbium. Scale bars: 1 mm (A, B, E, F), 0.5 mm (C, H), 0.2 mm (I) 0.1 mm (D, G).

Figure 2. Loxosceles deformis Wunderlich, 1988, holotype (SMF-Be 968 a), photographs under light microscopy. A, B habitus, dorsal view. C left tibia I, prolateral. D palps, subventral view. E right palp, retrolateral view. F right bulb, retrolateral view. Scale bars: 2 mm (A), 1 mm (B, C), 0.5 mm (D, E), 0.1 mm (F).