Emertongone, 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 : 525

EMERTONGONE GEN. NOV.

Type species: Lophocarenum montiferum Emerton, 1882 .

Derivatio nominis: The genus name is a combination of Emerton, in honor of the American arachnologist James Henry Emerton, the original describer of the type species, and the ending of the generic name ‘ Erigone ’. Genus gender feminine.

Diagnosis:

Males: Small-sized, dark-brown-coloured erigonine. This genus is characterized by its male prosomal modification comprising a post-PME groove, post- PME lobe, the anteriorly protruded hirsute clypeus and the shorter distance from PLE to clypeal lower margin compared to PME. Despite its superficial partial similarity of prosomal modification with Oe. gibbosus , this genus has no separate radix and embolus connected by a membranous region, and the embolic membrane is erected from distal part of distal suprategular apophysis. These characters distinguish it from all taxa in Clade 13.

Females: Can be distinguished from all other examined taxa by the shorter distance from ALE to clypeus margin compared to distance from AME to clypeus margin, the hirsute clypeus, and the transverse slit on the epigyne between the two copulatory openings ( Fig. 65E, G ).

Species included: Emertongone montifera ( Emerton, 1882) comb. nov.

Phylogenetic justification: Although the prosomal modification of Em. montifera superficially resembles that of Oe. gibbosus , the palpal configuration of this species is different from that of Oedothorax as delimited in the present study. In the phylogeny ( Fig. 2 ), this species is sister to Clade 12; i.e. more closely related to the Walkenaeria and Gonatium representatives than to all Oedothorax , Callitrichia , Mitrager and other representatives in Clade 13. The similarity in prosomal morphology is, therefore, a result of homoplasy. 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 resulting phylogenetic placement, this species neither belongs to Oedothorax , nor can it be transferred to any other established taxon.We, therefore, propose the erection of Emertongone gen. nov. for this unique 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 65. Mitrager villosa (Tanasevitch, 2015). A, male left palp, retrolateral view. B–E, male right palp, images flipped horizontally. B, retrolateral view. C, prolateral view. D, dorsal view. E, embolic division, prolateral view. F–I, epigyne. F, posterior view. G, ventral view. H, dorsal view. I, external morphology. J, male spinnerets. K, female spinnerets. Scale bars 0.1 mm.