Phalangiotarbi ( Haase, 1890) is an extinct arachnid order first recorded from the Early Devonian of Germany and most widespread in the Upper Carboniferous coal measures of Europe and North America. The last species are known from the early Permian Rotliegendof Germany.
The affinities of phalangiotarbids are obscure, with most authors favouring affinities with Opiliones (harvestmen) and/or Acari (mites and ticks). Phalangiotarbida has been recently (2004) proposed to be sister group to ( Palpigradi+ Tetrapulmonata): the taxon Megoperculata sensu Shultz (1990).
Nemastomoides depressus, described as a harvestman in the family Nemastomoididae, is actually a poorly preserved phalangiotarbid.