Leptopsalis Thorell, 1882

Bartel, Christian, Dunlop, Jason A. & Giribet, Gonzalo, 2023, An unexpected diversity of Cyphophthalmi (Arachnida: Opiliones) in Upper Cretaceous Burmese amber, Zootaxa 5296 (3), pp. 421-445 : 425-426

Genus Leptopsalis Thorell, 1882

Type species. Leptopsalis beccarii Thorell, 1882 .

Diagnosis. See Clouse 2012.

Remarks. The holotype of Leptopsalis breyeri sp. nov. (MB.A.4457; Figs. 3–4 ) is an adult male, because of its large size and the presence of an adenostyle on tarsus IV. This specimen can be reliably identified as a member of the family Stylocellidae . The ornamented second cheliceral segment, type 2 ozophores, free sternites, C-shaped spiracles and the position of the fringed adenostyle are typical characters for representatives of this family. The possible presence of eyes and indistinctly curved opisthosomal sternal sulci combined with the absence of anal gland pores and extensive cheliceral sculpturing suggest affinities to the extant genus Leptopsalis . Furthermore, the habitus of this fossil is somewhat similar to that of the holotype of Sirocellus iunctus sp. nov. (GPIH05128) described above. However, specimen MB.A.4457 is much larger and features a completely different adenostyle on tarsus IV. The latter cannot be observed in any of the extant species of Leptopsalis , which often have a rather small adenostyle. Based on these characters, this fossil is provisionally placed as an extinct species of Leptopsalis . However, we should keep in mind that some of the characters are possibly plesiomorphic, like the mostly straight opisthosomal sternal sulci, which is the predominant form observed in all our fossils.

Figures

FIGURE 3. Leptopsalis breyeri sp. nov., male holotype (MB.A.4457). A. Whole specimen, dorsolateral view. B. Same, ventral view. C. Camera lucida drawing of A. D. Same of B. Abbreviations: ad, adenostyle; ap, anal plate; ch, chelicerae; fe, femur; mt, metatarsus; oz, ozophore; pa, patella; pp, pedipalp; ta, tarsus; ti, tibia; tr, trochanter; legs numbered from I–IV. Scale bars equal 1 mm.

FIGURE 4. Details of Leptopsalis breyeri sp. nov., male holotype (MB.A.4457).A. Close-up of tarsus IV. B. Close-up of ventral side of opisthosoma. Abbreviations: ad, adenostyle; ap, anal plate; sp, spiracle; leg IV numbered. Scale bars equal 0.5 mm.