Sirocellus iunctus, Bartel & Dunlop & Giribet, 2023

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 : 424

Species Sirocellus iunctus sp. nov.

Fig. 1

urn:lsid:zoobank.org:act:EF263CC3-F2A9-45E8-A237-9830DDB5B49B

Holotype. GPIH05128 , ex coll. Patrick Müller, BUB3113.

Type-locality. Myanmar, Hukawng Valley; Burmese amber. Upper Cretaceous (Lower Cenomanian).

Etymology. Latin “iunctus” (= combined), referring to the unique combination of characters of this species.

Diagnosis. As for the genus.

Description. Body oval, with an almost conical rear; almost all of cuticle with a tuberculate-microgranular microstructure ( Fig. 1A, C ), total L 1.96, maximum prosomal W behind ozophores 0.48, maximum opisthosomal W 0.55. Ozophores almost conical, in type 2 position. L of ozophores 0.17, W at base 0.14, distance between base of ozophores 0.29. Chelicerae long and mostly smooth, with a few small granules and three larger tubercles on chela ( Fig. 1B–D ); dentition equivocal; basal segment L 0.43, chela 0.39. Pedipalps moderately long and thin, with few sensory setae on tarsus; pedipalp tarsus with a small claw on its tip; pedipalp length: tr?, fe?, pa 0.21, ti 0.24, ta 0.22. Legs robust and covered with numerous setae on tarsus and metatarsus; additionally, all legs granular, with small, partly setiferous tubercles; tarsus IV bearing a large lamelliform adenostyle proximally; leg tarsi not subdivided, bearing a single smooth claw; leg lengths: I tr 0.21, fe 0.37, pa 0.26, ti 0.38, mt 0.27, ta 0.45, total 1.94; II tr 0.20, fe 0.41, pa 0.21, ti 0.38, mt 0.22, ta 0.46, total 1.88; III tr 0.21, fe 0.41, pa 0.21, ti 0.36, mt 0.19, ta 0.36, total 1.74; IV tr 0.21, fe 0.43, pa 0.24*, ti 0.40, mt 0.28, ta 0.37*, total 1.93. Opisthosomal sternites granular, with relatively straight and parallel sulci ( Fig. 1B, D ). Spiracles equivocal. Anal plate not observed.

Figures

FIGURE 1. Sirocellus iunctus gen. et sp. nov., male holotype (GPIH05128). A. Whole specimen, dorsolateral view. B. Same, ventrolateral view. C. Camera lucida drawing of A. D. Same of B. Abbreviations: ad, adenostyle; 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 (A, C, D) and 0.5 mm (B).