Figure 1

Distribution of the 3248 occurrence records (black dots) of the European stygobitic harpacticoid species in the three groundwater habitat types30 (freely available to: https://atlas.freshwaterbiodiversity.eu/index.php/explore/item/66-groundwater-habitats-europe-atlasapp): aquifers in consolidated rocks (CONS), aquifers in unconsolidated sediments (UNCONS), and practically non-aquiferous rocks (NonAQ). Features such as “glaciers”, “lacustrine waters”, and “freshwater bodies” were represented to enhance readability (map generated by ArcMap 10.055; https://www.esri.com).