Liomma Roewer, 1959

Kury, Adriano B., Villarreal, Osvaldo & Medrano, Miguel, 2024, On the systematic allocation of Liomma Roewer, 1959 (Arachnida: Opiliones: Nomoclastidae) and discovery of a putative synapomorphy for Nomoclastinae, Journal of Natural History 58 (1 - 4), pp. 1-13 : 4-5

Genus Liomma Roewer, 1959

Liomma Roewer 1959: 72

[type species: Liomma laeve Roewer,1959 , by original designation]

Liomma – Kury 2003: 25 (cat.)

Placement

Originally in Tricommatinae, removed to Grassatores incertae sedis by Kury (2003). Transferred herein to Nomoclastidae : Nomoclastinae NEW FAMILIAL ASSIGNMENT.

Included species

Liomma laeve Roewer, 1959 .

Etymology

From Greek λεῖος (smooth) + ὄμμα (eye). Possibly referring to the unarmed and glossy ocularium. Gender neuter.

Diagnosis

Medium-sized nomoclastines (dorsal scutum length about 4.4 mm). Dorsal scutum rectangular, with coda region flaring. In the female, scutum is trapezoidal with two well-marked constrictions. Ocularium very wide (not so much in the females) ( Figures 4a , 6a ), not especially high. Chelicera and pedipalpus sexually dimorphic, extremely robust in male: basichelicerite stout, cheliceral hand kidney-like, swollen, pedipalp articles, especially femur, thickened and bearing immense dorsal protuberance. Metatarsus I sexually dimorphic, swollen only in male with a row of 19 short MtCS ( Figure 2a–c ). Legs I–IV short and thin, contrasting with the sturdy body. Ventral plate trapezoid with rounded corners. Glans complex not sunken in a circular pit. Glans sac rectangular, multi-folded with ventral inflatable sac ( Figure 5c–f ). Stylus thick, thumb-shaped, situated atop the glans sac. Macrosetae C1–C3, A1–A2 cylindrical elongate, laterally inserted. Macrosetae B absent. Macrosetae D and E extremely reduced ( Figure 5d–f ). See discussion below for comparison of characters within the subfamily. Males with short comb of MtCS positioned on the distal third of the metatarsus.

Figures

Figure 2. Liomma laeve, male (MNRJ 19235). Right metatarsus I: a. dorsal view; b. mesoapical view; c. detail of modified setae. Zamora granulata (MNRJ 19266): d–g. Metatarsus I; d. dorsal view; e. subapical portion in mesal view; f. tarsomeres I; g. calcaneus, dorsal view.

Figure 4. Liomma laeve, male (MNRJ 19235) from Baños: a. habitus, dorsal view; b. same, ventral view; c. same, right lateral view; d. same, frontal view. Scale bars = 1 mm.

Figure 5. Liomma laeve, male (MNRJ 19235) from Baños: a. left pedipalpus mesal view; b. same, ectal view; c. penis, distal part, dorsal view; d. same, ventral view; e. same, panoramic lateral view; f. same, lateral view. Scale bars: a = 0.5 mm; b = 1.0 mm; c, d, f = 0.05 mm; e = 0.1 mm.

Figure 6. Liomma laeve, male (MNRJ 19235) from Baños: a. habitus, dorsal view; b. same, left lateral view; c. female (MNRJ 19235), left lateral view. Penis (MNRJ 19235): d. dorsal view; e. ventrolateral view; f. lateral view. Scale bars: a–c = 1 mm; d–f = 0.05 mm.