Gymnobisiidae Beier, 1947: 287–288; Muchmore, 1972: 268; Harvey, 1992: 1408–1409; Harvey, 1996: 258; Harvey et al. 2016: 75–76, 79.
Type Genus: Gymnobisium Beier, 1931.
Remarks. According to Harvey (1992) the Gymnobisiidae have the following apomorphies: thickened spine-like seta present distally on movable chelal finger and prolaterally from the teeth, male genitalia that are greatly enlarged, and absence of a venom apparatus in the fixed chelal finger.
Further diagnostic characters include a movable chelal finger with a noticeably expanded nodus ramosus; both chelal fingers possessing lightly sclerotized, juxtadentate teeth on thin lamellae; the fixed chelal finger with a short row of highly sclerotized teeth, located terminally, and often accompanied by a single or multiple accessory teeth; the presence of a groove, proximal to the sclerotized teeth row, that receives the venedens of the movable finger; trichobothria eb, esb, ib, isb and ist clustered in a group at the base of the fixed chelal finger, with est, it and et grouping distally; the presence of a condyle on the retrolateral margin of each chelal hand; galea branched into multiple rami; suture line between leg IV femur and patella perpendicular (Muchmore 1972).