Solenysa, a Cretaceous Relict Spider Group in East Asia

Abstract

A time scale of phylogenetic relationships contributes to a better understanding of the evolutionary history of organisms. Herein, we investigate the temporal divergence pattern that gave rise to the poor species diversity of the spider genus Solenysa in contrast with the other six major clades within linyphiids. We reconstructed a dated phylogeny of linyphiids based on multi-locus sequence data. We found that Solenysa diverged from other linyphiids early in the Cretaceous (79.29 mya), while its further diversification has been delayed until the middle Oligocene (28.62 mya). Its diversification trend is different from all of the other major lineages of linyphiids but is closely related with the Cenozoic ecosystem transition caused by global climate changes. Our results suggest that Solenysa is a Cretaceous relict group, which survived the mass extinction around the K-T boundary. Its low species diversity, extremely asymmetric with its sister group, is largely an evolutionary legacy of such a relict history, a long-time lag in its early evolutionary history that delayed its diversification. The limited distribution of Solenysa species might be related to their extreme dependence on highly humid environments.

Sheet Webs of Linyphioid Spiders (Araneae: Linyphiidae, Pimoidae): The Light of Diversity Hidden Under a Linguistic Basket

“…Subsequent molecular work that used the same genes but with a much larger taxon sample (Dimitrov et al 2012, 2017; Wang et al, 2015; Tian et al, 2022) has corroborated many of those groups but also suggested a much more complex picture of the phylogeny of Linyphiidae. All more recent analyses have confirmed the hypothesis of Arnedo et al (2009) that micronetines are paraphyletic.…”

Phylogenomic, Biogeographic, and Evolutionary Research Trends in Arachnology

“…Many factors can be at play, including diversification and extinction tempos. In a paper titled "Solenysa, a Cretaceous Relict Spider Group in East Asia" [4], Jiahui Tian and colleagues explore the long evolutionary history of one of the major clades of linyphiids and the reasons for its relative poverty in species diversity compared with the other linyphiid lineages. The authors found that Solenysa diverged from other linyphiids in the Cretaceous and underwent diversification stasis well into Oligocene.…”