Libitia Simon, 1879

Medrano, Miguel, Ázara, Ludson Neves de & Kury, Adriano Brilhante, 2020, The short-legged Andean cosmetids revisited: the genus Libitia Simon, 1879 with description of two new species (Opiliones, Cosmetidae), European Journal of Taxonomy 634, pp. 1-25 : 4-5

Genus Libitia Simon, 1879

Libitia Simon, 1879: 216 [type species: Cosmetus cordatus Gervais, 1844 , by subsequent designation of Roewer (1912)].

Libitiella Roewer, 1947: 8 [type species: Libitia bipunctata Sørensen, 1932 , by original designation]. syn. nov.

Libitia – Simon 1880: 103 — Roewer 1912: 11; 1923: 293. — Mello-Leitão 1923: 108; 1926: 331; 1932: 53; 1933: 105, 109; 1935: 113. — Kästner 1937: 389. — Kury 2003: 65 (revalidated) [junior subjective synonym of Vonones Simon, 1879 by Goodnight & Goodnight (1953: 59)].

Libitia (Libitia) – Sørensen in Henriksen 1932: 417.

non Libita [subsequent incorrect spelling] – Roewer 1928: 552.

Etymology

Obscure, it sounds to us as a Roman woman’s name. Gender feminine.

Diagnosis

Can be differentiated in having shorter legs (femur IV shorter than the total length of the dorsal scutum) contrasting with other short-legged cosmetids as Rhaucus Simon, 1879 , Neocynorta or Eulibitia (its femur IV is longer than dorsal scutum length) ( Fig. 1B , E–F). Outline of dorsal scutum alpha-type with faint marked constrictions forming a parallel coda in males and divergent coda in females contrasting with Ambatoiella that has well-marked constrictions ( Figs 2 , 6 ). Can be separated from other genera by having cheliceral sockets (invaginations in the anterior margin of the carapace where the basichelicerites fit) shallow, with well-marked lateral quadrangular projections (triangular in Eulibitia , rounded in Rhaucus , bifid in Metalibitia ) ( Figs 2 , 6 ). Posterior margin of DS without yellow stripe (transversal stripe in Eulibitia and some Rhaucus species) ( Fig. 1 A–D). Basitarsomeres I, III and IV remarkably enlarged in males ( Figs 1B , 5B, D , 9 C–D). Penis with an elongate wattle in stylus forming distally two long serrate membranes and with a medial cleft ( Fig. 5 ), without stylar barbs.

Description

Small and flat animals (<4 mm) with short legs ( Fig. 1B ). Outline of dorsal scutum alpha-type with symmetrical mid-bulge ( Fig. 2 ).

Mesotergum flat and unarmed. Scutum with yellowish white blots as a ‘ladder mask’ over dark brown background (see Medrano & Kury 2016, 2017), with intraspecific variation from absent ( Fig. 2 ) to strongly filled invading the entire area I and II ( Fig. 6 ) or part of carapace ( Fig. 9A ).

Coxa IV entirely visible in dorsal view, without groin warts (defined in Kury & Barros, 2014) and small prodorsal distal apophysis. Femur III and IV curved and uniformly tuberculate ( Fig. 1B ).

Penis ( Fig. 4 ): ventral plate (VP) sub-rectangular with latero-apical borders protruding from the ventral plate, stylus with an incrassated wattle forming apically two long serrate membranes creating a medial cleft ( Fig. 4D ), without stylar barbs. VP laterally with two pairs of MS A, two pairs of MS C (sometimes asymmetrical with 3 MS C on one side, as in L. bipunctata and L. gandalf sp. nov.), two pairs of MS D (D1 three times longer than D2), and ventrally with two pairs of MS E and one pair MS B ( Fig. 4C ).

Note

As no diagnostic differences have been found among the penes of each of the four species, no specific descriptions are made.

Included species

Libitia cordata ( Gervais, 1844) , Libitia bipunctata Sørensen, 1932 , Libitia gandalf sp. nov. and Libitia iguaque sp. nov.

Geographic distribution

Central part of Eastern Cordillera of Andes from 2600 to 3700 meters, in Cundinamarca, Boyacá and Meta departments of Colombia.

Figures

Fig. 1. Libitia bipunctata Sørensen, 1932, ♂ (ICN-AO 1040), habitus. A. Dorsal view. B. Dorsal view, panoramic. C. Frontal view. D. Lateral right view. E–F. Right femur IV, dorsal and ventral view, respectively. Scale bars = 1 mm.

Fig. 2. Libitia bipunctata Sørensen, 1932, variation of spot pattern on dorsal scutum. A–D. ♂♂. A. IAvH-I-67. B. ICN-AO 468. C. ICN-AO 419. D. IAvH-I-87. E–H. ♀♀. E. IAvH-I-76. F–H. UNAL- AO 420. Scale bar = 1 mm.

Fig. 6. Libitia cordata (Gervais, 1844), variation of spot pattern on dorsal scutum. A–D. ♂♂. A. ICN-AO 1040. B. ICN-AO 421. C. ICN-AO 1040. D. ICN-AO 1040. E–H. ♀♀. E–F. ICN-AO 421. G–H. ICN-AO 1040. Scale bar = 1 mm.

Fig. 5. Libitia cordata (Gervais, 1844), ♂ (ICN-AO 1040), habitus. A. Dorsal view. B. Dorsal view, panoramic. C. Frontal view. D. Lateral right view. Scale bars = 1 mm.

Fig. 9. Libitia gandalf sp. nov., holotype, ♂ (IAvH-I-69), habitus. A. Dorsal view. B. Dorsal view, anterior margin of carapace. C. Dorsal view, panoramic. D. Frontal view. E. Right lateral view. F–G. Right femur IV, dorsal and ventral view, respectively. Scale bars = 1 mm.

Fig. 4. Libitia bipunctata Sørensen, 1932, ♂ (ICN-AO 419), distal part of penis. A. Dorsal view B. Right lateral view. C. Ventral view, macrosetae colorised and numbered. D. Stylus, dorsal view. Scale bars: A–C = 50 μm; D = 20 μm.