Phylogenetic relationships of the comb-footed spider subfamily Spintharinae (Araneae, Araneoidea, Theridiidae), with generic diagnoses and a key to the genera

Abstract

The monophyly of Spintharinae is supported in agreement with previous analysis of Theridiidae by Agnarsson and Arnedo et al. We study the relationships of the genera within Spintharinae. Fourteen species in the genera Chrosiothes, Episinus, Spintharus, Stemmops, and Thwaitesia constituted the ingroup, while five species from the genera Euryopis and Dipoena (Hadrotarsinae), as well as Latrodectus and Steatoda (Latrodectinae), served as outgroup taxa. The character matrix included 49 morphological characters. Parsimony analyses using several character weighting strategies supported the monophyly of Spintharinae with Stemmops as sister to a clade that includes the remaining ingroup taxa. Chrosiothes emerged as sister to Episinus + Spintharus + Thwaitesia which formed a polytomy. The equally weighted, successive weighted, and preferred implied weight topologies, were all logically consistent. A key to the genera of Spintharinae and diagnoses for each genus are given.

A radiation of the ornate Caribbean ‘smiley-faced spiders’, with descriptions of 15 new species (Araneae: Theridiidae, Spintharus)

“…1A), with sticky globules near substrate (Eberhard et al, 2008). See Hentz (1850), Levi (1954aLevi ( , 1963a and Durán-Barrón et al (2013) for additional descriptions and diagnoses.…”

“…The genus was present in the higher-level phylogenetic analyses of Agnarsson (2004) based on morphology, and the molecular studies of Arnedo et al (2004) and Liu et al (2016). An analysis of morphological data, focusing on spintarines, was then presented by Durán- Barrón, Rosas & Contreras-Ramos (2013). These studies have strongly supported the monophyly of Spintharinae, but do not agree on the exact placement of Spintharus.…”

“…These studies have strongly supported the monophyly of Spintharinae, but do not agree on the exact placement of Spintharus. Based on molecular data, Spintharus is probably sister to Chrosiothes (Liu et al, 2016), but morphology is ambiguous as to its placement (Durán-Barrón et al, 2013). The first species-level molecular phylogenetic data for Spintharus was published only recently by Dziki et al (2015), based on specimens freshly sampled throughout the Caribbean and on neighbouring continents.…”

Description and phylogenetic analysis of two new Episinus (Araneae, Theridiidae) species from China

“…The genera Spintharus, Thwaitesia, and Episinus all tend to build an H-shaped web with the animal facing downwards and holding onto parts of the web with its feet, presumably specializing on pedestrian prey such as ants (Agnarsson 2004;Eberhard et al 2008). A close relationship between Thwaitesia and Epsisnus was proposed by Durán-Barron et al (2013) based on morphology. However, also based on morphology, Rodrigues et al (2022), found that Thwaitesia is unrelated to Episinus, and morphological evidence showed that humps are present on the abdomen in Episinus but absent in Thwaitesia.…”

Revisão e análise cladística das espécies do gênero Moyosi Miller, 2007 (Araneae, Linyphiidae, Erigoninae)

“…Apesar de não haver um valor padrão de k, e sua escolha parecer arbitrária entre cada autor, ainda é preferível valores baixos, principalmente entre k=1 e k=10 (Goloboff, 1993;Goloboff et al, 2008;Ramírez, 2003;Agnarsson, 2004;Arnedo et al, 2009;Frick et al, 2010;Mendes, 2011;Durán-Barrón et al, 2013;Gavish-Regev et al, 2013;Frick & Scharff, 2013). No entanto, neste estudo, para explorar os resultados desses valores de k, e tentar obter variados parâmetros para testar a estabilidade dos clados, foram estipulados para constante k=1- 15,20,25,30,35,40,45, 50 e 100.…”