Arthropod diversity in Iran: subphylum Hexapoda Latreille, 1825, basal hexapod taxa.

A comprehensive review of the literature and database records on the five lineages of basal hexapods of Iran was conducted to summarise current knowledge of their diversity and distribution within the country. A total of 379 species are currently known from Iran, belonging to 140 genera and 27 families. Collembola are the most diverse (345 species, 119 genera, 20 families), followed by Zygentoma (21 species, 10 genera, 3 families) and Archaeognatha (6 species, 5 genera, 1 family), whereas Protura (5 species, 4 genera, 2 families) and Diplura (2 species, 1 genus, 1 family) remain clearly under-sampled. Collembola have been recorded from many regions of Iran, especially the north, whereas for the other groups few or no species are known from most provinces. Most species for which Iranian habitat data are available occur only in forest environments, particularly the Hyrcanian forests. Fifty-one Collembola species (≈14.8%) and 15 non-Collembola taxa (e.g., Protura, Archaeognatha and Zygentoma) are known only from Iran and are likely endemic, indicating that the country is a regional diversity hotspot in Western Asia. Studies on basal taxa, especially Collembola, have increased the number of recorded species from 70 to 345 over the past 43 years. Nevertheless, additional research in specific environments, particularly in eastern, central, western, and southern Iran, is still needed. This quantitative overview reveals clear geographic and taxonomic gaps that future surveys must address to refine biodiversity and conservation priorities nationwide.