Architarbi Phalangiotarbi Phalangiotarbida 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.

[1] The last species are known from the early Permian Rotliegend of 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).

[2] Nemastomoides depressus, described as a harvestman in the family Nemastomoididae, is actually a poorly preserved phalangiotarbid.