Cornitibia, Lin & Lopardo & Uhl, 2022

Lin, Shou-Wang, Lopardo, Lara & Uhl, Gabriele, 2022, Evolution of nuptial-gift-related male prosomal structures: taxonomic revision and cladistic analysis of the genus Oedothorax (Araneae: Linyphiidae: Erigoninae), Zoological Journal of the Linnean Society 195, pp. 417-584 : 529

CORNITIBIA GEN. NOV.

Type species: Oedothorax simplicithorax Tanasevitch, 1998

Derivatio nominis: The genus name refers to the tusklike male palpal tibia apophysis of the type species. Genus gender feminine.

Diagnosis:

Males: This genus is distinguished from all other erigonines by the distinct male palpal tibia, bearing one tusk-like, seta-free apophysis rising from the proximal half of tibia and pointing apically, and several long thorns from enlarged setal bases both retrolateral and prolateral to the apophysis, as well as by the unique morphology of the embolic division (as shown in Fig. 69D ). The lack of a membranous connection between the radix and the embolus and the presence of radical lateral tooth clearly distinguish this species from all taxa on Clade 13.

Females: Unknown.

Species included: Cornitibia simplicithorax (Tanasevitch, 1998) comb. nov.

Phylogenetic justification: In the original description of Oedothorax simplicithorax (Tanasevitch 1998) , no account was given regarding the diagnostic characters used for assigning this species to Oedothorax , and the embolic division of this species was not clearly illustrated. Later ( Tanasevitch, 2015), diagnostic characteristics of Oedothorax were described, including features related to the embolic division, which match most species on Clade 13. Examination of Co. simplicithorax revealed a greatly different embolic division configuration in this species, with an pale, ventro-prolaterally situated ‘anterior radical process’, different from that of other species examined in the present study. In the phylogeny ( Fig. 2 ), this species is sister to a clade comprising the majority of our taxon sample (Clade 10), and not closely related to Oedothorax , Callitrichia , Mitrager or other taxa in Clade 13. After a comprehensive literature research of erigonine male palpal structures, no morphologically resembling species was found that can suggest at least a preliminary (i.e. phenetic) close relatedness. Base on these findings and its relatively basal phylogenetic placement, this species neither belongs to Oedothorax , nor can it be transferred to any other established taxon. We, therefore, propose the erection of Cornitibia gen. nov. for this species.

Figures

Figure 2. The first part of the three most-parsimonious trees generated from the analysis of Matrix II, with Bremer/ Jackknife support valuesshown beside nodes.The presence/absence of clades in the consensus trees of the most-parsimonious trees of the implied weights analysis with different k values are shown in the box under/on the branches: black for presence when considering all taxa; grey for presence only when Callitrichia convector (Tanasevitch, 2014) and Ca. usitata (Jocqué & Scharff, 1986) are not considered; white for absence.

Figure 69. Cornitibia simplicithorax (Tanasevitch, 1998). A–D, male left palp. A, retrolateral view. B, prolateral view. C, dorsal view. D, ventral view. E, male spinnerets. Scale bar 0.1 mm.