As of July 2016, the International Union for Conservation of Nature (IUCN) lists 394 critically endangered arthropod species, including 86 which are tagged as possibly extinct. 4.1% of all evaluated arthropod species are listed as critically endangered. The IUCN also lists three arthropod subspecies as critically endangered.
No subpopulations of arthropods have been evaluated by the IUCN.
Additionally 2875 arthropod species (30% of those evaluated) are listed as data deficient, meaning there is insufficient information for a full assessment of conservation status. As these species typically have small distributions and/or populations, they are intrinsically likely to be threatened, according to the IUCN. While the category of data deficient indicates that no assessment of extinction risk has been made for the taxa, the IUCN notes that it may be appropriate to give them "the same degree of attention as threatened taxa, at least until their status can be assessed."
This is a complete list of critically endangered arthropod species and subspecies as evaluated by the IUCN. Species considered possibly extinct by the IUCN are marked as such.