The placement of the spider genus Periegops and the phylogeny of Scytodoidea (Araneae: Araneomorphae)

Abstract

The relationships of Scytodoidea, including the families Drymusidae, Periegopidae, Scytodidae and Sicariidae, have been contentious for a long time. Here we present a reviewed phylogenetic analysis of scytodoid spiders, emphasizing Periegops, the only genus in the family Periegopidae. In our analysis the Scytodoidea are united by the fusion of the third abdominal entapophyses into a median lobe, the presence of female palpal femoral thorns and associated cheliceral stridulatory ridges, a membranous lobe on the cheliceral promargin, and the loss of minor ampullate gland spigots. A basal split within Scytodoidea defines two monophyletic groups: Sicariidae and a group formed by Scytodidae as the sister group of Periegopidae plus Drymusidae, all united by having bipectinate prolateral claws on tarsi I–II, one major ampullate spigot accompanied by a nubbin, and the posterior median spinnerets with a mesal field of spicules. Periegops is the sister group of Drymusidae, united by the regain of promarginal cheliceral teeth and a triangular cheliceral lamina, which is continuous with the paturon margin.