Taxonomy
The family Ctenidae comprises 40 genera and 490 species in The World Spider Catalog (Version 14.0 by Norman I. Platnick). We here restrict ourselves to the Neotropical spiders.
Neotropical ctenids are medium to very large, mostly robust wandering spiders with strong legs and two tarsal claws (or a third reduced claw). The eye pattern is typical (called ctenoid): eight eyes in three rows (2-4-2 in dorsal view). Chelicerae are usually strong and some species have very strong venom.
To enable further taxonomic work on Ctenidae Brescovit & Simó (2007) designed a neotype for the type species of the genus Ctenus dubius Walckenaer, 1805 which is definitely lost. Type specimens were chosen from the type locality Cayenne in French Guiana. Based on this decision two characters are recognized as putative synapomorphies for the genus: protruding ovoid lobes in the middle field of the epigynal plate of the females and an embolus with a basal projection in males.
Thereupon several Neotropical ctenid genera were revised (Isoctenus, Gephyroctenus), some genera newly synonymized with Ctenus (Oligoctenus), new genera (Chococtenus, Ohvida, Parabatinga, Toca) and several new species described (Brescovit & Polotow 2005; Polotow & Brescovit 2006, 2008, 2009a-d, 2011, 2012, 2013; Dupérré 2015; Hazzi et al. 2018).
The belonging of Ancylometes and Cupiennius to the Ctenidae is still doubtful. Although most ctenids are two-clawed as adults, species in several genera show an inferior tarsal claw in early instars. A reduced third claw is present in the two genera Ancylometes and Cupiennius, which were therefore considered sister- and basal groups within the higher ctenids by Silva Davila (2003). In a more recent analysis Cupiennius was considered not being a ctenid by Polotow, Carmichael & Griswold (2015), who did not assign Cupiennius to any recognised family.
The genus Itatiaya Mello-Leitão, 1915 was transferred to the Zoropsidae (Polotow & Brescovit 2011). The genus Paravulsor is considered to not belong to the ctenids.