RTA clade

The RTA clade is a clade of araneomorph spiders, united by the possession of a retrolateral tibial apophysis – a backward-facing projection on the tibia of the male pedipalp. The clade contains over 21,000 species, almost half the current total of about 46,000 known species of spider. Most of the members of the clade are wanderers and do not build webs. Despite making up approximately half of all modern spider diversity, there are no unambiguous records of the group from the Mesozoic and molecular clock evidence suggests that the group began to diversify during the Late Cretaceous.

Families
In 2005, Coddington included 39 families in a cladogram showing the RTA clade:


 * Agelenidae
 * Amaurobiidae
 * Ammoxenidae
 * Amphinectidae (paraphyletic; merged into Desidae)
 * Anyphaenidae
 * Cithaeronidae
 * Clubionidae
 * Corinnidae
 * Cryptothelidae
 * Ctenidae
 * Desidae
 * Dictynidae
 * Gallieniellidae
 * Gnaphosidae
 * Lamponidae
 * Liocranidae
 * Lycosidae
 * Miturgidae (paraphyletic)
 * Oxyopidae
 * Philodromidae
 * Phyxelididae
 * Pisauridae
 * Psechridae
 * Salticidae
 * Selenopidae
 * Senoculidae
 * Sparassidae
 * Stiphidiidae
 * Tengellidae (now merged into Zoropsidae)
 * Thomisidae
 * Titanoecidae
 * Trechaleidae
 * Trochanteriidae
 * Zodariidae
 * Zoridae (now a synonym of Miturgidae)
 * Zorocratidae (no longer accepted; most genera now placed in Udubidae)
 * Zoropsidae