In 1892, Eugène Simon based the group, which he noted was only weakly homogeneous, on the presence of divided tarsal scopulae.

This feature was later considered to be plesiomorphic (i.e. potentially inherited from an ancestor by multiple descendant groups), and both morphological and molecular phylogenetic studies have shown that, as traditionally circumscribed, the subfamily is not monophyletic.

Following Ausserer's characterization of the genus, Simon used the divided tarsal scopulae as the defining characteristic of the group.

However, Simon noted that "à part ce caractère .. les Ischnocoleae n'ont guère de particularités communes et ils forment un ensemble peu homogène" (apart from this character .. the Ischnocoleae have hardly any common characteristics and they form a weakly homogeneous set).

[4] In his 1985 monograph on the Mygalomorphae, Robert Raven considered the divided tarsal scopulae to be a plesiomorphic character and the Ischnocolinae to be non-monophyletic, treating it as Theraphosidae incertae sedis.

[5] In 2014, a molecular phylogenetic study was published that confirmed the non-monophyly of Ischnocolinae when broadly defined.