Parasironidae Karaman & Mitov & Snegovaya 2024, fam. nov.
Creators: name: Karaman, Ivo M.
name: Mitov, Plamen G.
name: Snegovaya, Nataly
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Opiliones
Parasironidae

description: Family Parasironidae fam. nov.
urn:lsid:zoobank.org:act: 16C321F5-58A2-4E36-AEA3-FEB4A8B02583
Type genus
Parasiro Hansen & Sørensen, 1904.
Included genera
Parasiro Hansen & Sørensen, 1904, Cimmerosiro gen. nov., Tirrenosiro gen. nov. and Ebrosiro gen. nov.
Diagnosis
Most of the diagnostic characters here presented were given by Juberthie (1958) as diagnostic characters for the genus Parasiro. Small to medium-sized species. Ozophores located on lateral edges of dorsum (type 1 after Juberthie 1970). Narrow frontal edge of dorsum closely covers basal article of chelicerae on its terminal half, after which basal article of chelicerae rises sharply on its dorsal side, forming a prominent transverse ridge. At height of transverse ridge of chelicerae, a medially oriented ventral process present. Distal cheliceral article wide and stout (its basal part twice as long as wide). Pedipalp tibia as long as or longer than tarsus. Coxal lobes I wide, in basal part as long as wide; basal part longer than distal part; coxal endites I continuous along its entire length. Coxal lobes II cup-shaped; about 2.5 times (2.3–2.7) as wide as long, with almost straight frontal margins. Metatarsi of legs elongated (longer than half of tarsal length), first two pairs subdivided in ornamented astragalus and smooth calcaneus (Fig. 1 А). Claws of legs III–IV with teeth (Fig. 1B–F) (also II in all except Cimmerosiro rhodiensis gen et sp. nov.). Corona analis: sternites 8 and 9 medially fused, tergite IX free. Sensitive structures named “subapical process” or “processus sensitif” (Juberthie 2000) (Fig. 2A–E) located dorsally on tarsi of legs I–II conspicuous and not tapering toward distal portion at all (Willemart & Giribet 2010) or only shortly near tip. Female genital orifice posterior margin thick, wide and smooth (Fig. 2F). Ovipositor short, with small number of articles (8–10). Ovipositor lobi without terminal plumose setae; setation concentrated on their dorsal side (Fig. 3), in Sironidae evenly distributed. Males without anal glands. In contrast to other Cyphophthalmi, this family is characterized by a rather uniform structure of the ventral prosomal compleX. The differences between the species of this family are more pronounced in the genital structures of both sexes.
Remarks
Working on this study, the first author discovered a hitherto unknown sensory organ (sensilla) of Cyphophthalmi, situated medially on the dorsal side of the pedipalp coxae (Fig. 4). It was overlooked in previous studies. In Sironidae (which were in focus), it is represented by a bristle-like structure and looks more like a mechanoreceptor. That structure is a differentiating character between members of the new family and Sironidae, from which it is here separated. In parasironids, the organ forms sensilla that are voluminous, with more or less expressed lobes (Figs 4 A-D), while in sironids they are more bristle-like (Fig. 5). A brief overview of a small sample of available material shows that this organ is present in most of Cyphophthalmi in various forms. It is not recognized in Tucanogovea shusteri Karaman, 2013 or a specimen of Metagovea sp. (Neogoveidae). In parasironids, it is membranous, more or less voluminous (they shrink when drying), suggesting a possible hygroreceptive role. It is similar in structure in Pettalidae and Suzukiellus sauteri (Roewer, 1916). In Ankaratra franzi Shear & Gruber, 1996 it seems more complex, as well as in Meghalaya sp. (Stylocellidae) (Fig. 4E–F). Perhaps this character may have some importance in phyletic analyses of Cyphophthalmi, and it is worth being investigated in more detail.
The structure of the pedipalp coxae shows a strong phylogenetic signal in Cyphophthalmi. They are remarkably different among representatives of two families. In Sironidae it is wider along the sagittal axis than long (Fig. 6A–C) and the articulation with the trochanter is eccentrically placed towards the ventral side. In Parasironidae (Fig. 6D) it is as wide as long, and the articulation is centered in the middle of its width. In addition, the pedipalp coxal lobi in Parasironidae are positioned more ventrally to the coxae compared to in Sironidae.
The setation of the ovipositor terminal lobi in Parasironidae is specific and remarkably different from the situation in Sironidae. Beside the absence of plumose setae, almost all setae are located on the dorsal side, while in Sironidae they are evenly distributed (Karaman 2009: figs 4–5). On the ventral side, there is only a pair of setae on the basal third of the lobi and a subterminal pair. This, together with the fact that the ventral prosomal complex is quite conservative in this group and that an anal gland is absent, suggests a possibly different way of spermatophore transfer than the one presented in Karaman (2005a). In Odontosiro lusitanicus Juberthie, 1962 the ovipositor setation is similar to that in parasironids, with the difference that one laterodistal seta is plumose (Juberthie 1962: fig. 9). This character mode may be a reflection of the phyletic closeness of this species to the family Parasironidae, despite numerous and significant differences, or a symplesiomorphic feature of phyletically distant taXa.
Characters such as the setation and number of claw teeth show a certain degree of variability among specimens and even aberrations, but do not affect their importance as differential characteristics between genera and species.
Distribution
Disjunct distribution in the Mediterranean from the eastern slopes of the Pyrenees in the west to the Transcaucasus in the east.
description: Published as part of Karaman, Ivo M., Mitov, Plamen G. & Snegovaya, Nataly, 2024, Parasironidae fam. nov., a Cimmerian lineage of Mediterranean Cyphophthalmi (Opiliones), with the description of three new genera and four new species, pp. 173-209 in European Journal of Taxonomy 921 (1) on pages 175-180, DOI: 10.5852/ejt.2024.921.2427, http://zenodo.org/record/10656519