Females have a genital plate (epigynum) and a "flow through" fertilization system; males have complex palpal bulbs.
Molecular phylogenetic studies have supported the monophyly of Entelegynae (whereas the other traditional subgroup, the Haplogynae, has been shown not to be monophyletic).
The ancestral (plesiomorphic) system is found in non-entelegyne spiders, where there is a single external genital opening in the female's abdomen.
[4] In 2016, a large molecular phylogenetic study was published online that included 932 spider species, representing all but one of the then known families.
[1] Filistatidae + Hypochilidae Synspermiata (ecribellate haplogynes) Austrochilidae + Gradungulidae + Leptonetidae (part) (paraphyletic) Palpimanoidea (paraphyletic in molecular analyses) Leptonetidae (part) Entelegynae Most members of the former Haplogynae are placed in the Synspermiata.