The Troglosironidae are a family of harvestmen with thirteen described species in a single genus, Troglosiro. Several species, including six undescribed ones, were collected around the island of New Caledonia, and more are expected to be found. Molecular data suggests that the Troglosironidae are related to Neogoveidae or Sironidae, but not to Pettalidae, as was proposed earlier. Troglosiro is endemic to New Caledonia. They are eyeless, small harvestman, 2.5 mm long at the most. Despite their name, they do not live exclusively in caves; several species have been found in forest litter.