The RTA clade is a clade of entelegyne Araneomorphae. It includes 39 families and around half of all known entelegyne species. Members of the RTA clade have a particular knob (or apophysis) on their palps known as the retrolateral tibial apophysis, ot RTA (Coddington and Levi 1991; Coddington 2005 and references therein). In many cases, the RTA apparently plays a role in facilitating copulation (Huber 1994, 1995).
(Coddington 2005)
