Erigoninae, Emerton, 1882

Silva-Moreira, Thiago Da, Kulkarni, Siddharth & Hormiga, Gustavo, 2025, A total evidence phylogenetic analysis of the spider family Linyphiidae (Araneae, Araneoidea), Zootaxa 5685 (1), pp. 1-78 : 57-58

Erigoninae ( Figs 9 , 12 )

Erigonines, commonly known as “dwarf spiders” or “money spiders,” is one of the oldest recognized groups within linyphiids. The name Erigoninae goes back to Simon’s (1884: 181) “erigonine,” and this subfamily is the most diverse linyphiid group. While most linyphiids have relatively uniform somatic morphology, many male erigonines exhibit a great diversity of cephalic modifications ( Hormiga, 2000). This diversity may have contributed at some point to their rank as a family— Erigonidae ( Gerhardt 1923) or Micryphantidae ( Bertkau 1878; Wiehle 1956, 1960). Some of the largest analyses of linyphiid phylogenetic relationships have the erigonines as the main focus ( Hormiga 2000; Miller & Hormiga 2004; Frick et al. 2010; Wang et al. 2015; Arnedo & Hormiga 2021; Lin et al. 2022). Erigonines are also the most diverse, species-rich group of linyphiids. Erigonines correspond to “Clade B” (partim) of Arnedo et al. (2009) and Wang et al. (2015). The monophyly of erigonines has been corroborated by phenotypic data (e.g., Hormiga 2000, Miller & Hormiga 2004 Tu & Hormiga 2011, Silva-Moreira & Hormiga 2022, Lin et al. 2022), but with the inclusion of molecular data ( Arnedo et al. 2009, Wang et al. 2015), classic erigonines form an unresolved clade with Microneta , Agyneta , Helophora (among other genera, see Wang et al. (2015)) nested within it. Arnedo et al. (2009, Fig. 9 ) do report that one of the trees that was used in forming the consensus of the hypothesis tree finds Erigoninae monophyletic, but all other analyses were congruent with Wang et al. (2015), recovering an “Erigonines + Micronetines” clade.

In our preferred hypothesis, erigonines are recovered as a natural group ( Fig. 9 ), and split in two major lineages . The first, the “ Neomaso clade,” contains Macrargus Dahl , Gongylidiellum Simon , Hilaira Simon , Millidgella Kammerer , Ostearius Hull , Laminacauda Millidge , and Neomaso Forster. The second is the “distal erigonines” clade (sensu Wang et al. 2015), the largest clade within Erigoninae in which Erigone Audouin is nested. Even considering the small taxon overlap between this study and Hormiga’s (2000) and Miller & Hormiga’s (2004), our results are congruent with the phenotypic analyses of those latter two studies. Erigoninae monophyly received, for the first time, the support of a large-scale total evidence analysis. The Neomaso clade is supported by seven synapomorphies, including the presence of a retrolateral groove in the cymbium (char 42), a paracymbium with a blunt edge (char 52), an embolic membrane without papillae (char 88), median (char 159) and lateral (char 160) eyes clustered and tracheolar taenidia (char 237). The Distal Erigonines lineage is supported by eight synapomorphies, including the branched medial tracheal trunks (char 234), much wider than the lateral ones (char 235), and invading the prosoma through the pedicel (char 236).

Some of our analyses recovered results similar to those of Arnedo et al. (2009) and Wang et al. (2015), where the Microneta clade is nested within the Neomaso clade or with some particular genera (notably Gongylidiellum ) recovered within the Microneta clade. All those topologies result from datasets that include the 28S sequences. As we discussed earlier, the inclusion of the 28S data results in topologies that contradict highly corroborated lineages. Given that we have considered those results artifactual and the finding of a monophyletic Erigoninae with strong phenotypic support, we regard the paraphyly of Erigonines in some analyses as another artifact caused by the inclusion of a marker with extreme size disparity. In our optimizations, Erigoninae is supported by 11 synapomorphies (all homoplastic), including the absence of macrosetae on the male palp tibia (char 6), male palp with a prolateral tibial apophysis (char 15), distal suprategular apophysis extending ventrally from the suprategulum (char 79) and females with a single clypeal seta below the AME (char 173).

None of the classic phenotypic diagnostic features of erigonines, such as the clawless female pedipalp (char 189) or the presence of a retrolateral tibial apophysis (char 17) in the male pedipalp, optimized as synapomorphies for this clade. This is due to the fact that those characters are being tested for the first time in a wider taxonomic context. Taxa previously placed in the erigonines based (in part) on those two characters, such as Labullinyphia tersa ( Benjamin & Hormiga, 2009) or Solenysa ( Tu & Hormiga 2011; contra Saaristo 2007), fall somewhere else in the tree once the molecular data are included.

Figures

FIGURE 9. Partial tree from the preferred hypothesis for linyphioids (M4_MB). Clade B (part), Erigoninae. Black arrow indicates the Erigoninae node. Black-colored squares represent nodes with posterior probability =1; gray-colored squares represent nodes with posterior probability between 0.95 and 0.99.

FIGURE 12. Optimization of the phenotypic matrix characters (DELTRAN optimization) on the pruned preferred hypothesis tree. Orange box indicates Clade A circumscription. Red box indicates Clade B circumscription. Black circles indicate nonhomoplasious optimizations (synapomorphies/ autapomorphies), while white circles indicate homoplasious transformations.