? 'Ninetine tarsal organ' (small
size, orifice <35% of diameter)(Huber 2000)
The tarsal organ of ninetines has a diameter of bout 3 µm, while in other pholcids the diameter varies between about 15-20 µm. In addition, the orifice is relatively small. Ninetine monophyly needs further study.
? Short walking
legs (tibia 1 <2.5x carapace width) and possibly
correlated characters (retrolateral trichobothrium very distal, few
pseudosegments)(Huber 2000)
It is not clear if short legs are plesiomorphic or derived. Most ninetines have very short legs, but short legs also occur in other genera (Anopsicus, Metagonia, Chibchea) where they are thought to represent adaptations to life in the leaf litter and interstices of the soil. This means that ninetine short legs might be derived too, and that they may have originated several times convergently.
(Astrin et al. 2007; Dimitrov et al. 2013)
Only a limited number of taxa and genes have been analyzed (Pholcophora and Ibotyporanga: CO1, 16S, 28S; Ninetis and an unidentified genus from Venezuela: only 28S), but at least these genera do indeed seem to be closely related (the inclusion of Holocnemus in the 28S tree must be considered an artifact).
