As part of Mara Knüsel’s impressive PhD work, we publisehd a paper in Ecography that explores how Late Pleistocene glaciation influenced the diversity and distribution of 36 groundwater amphipod species in the Alpine and peri-Alpine regions. It is based on a massive citizen science approach in collaboration with drinking water providers. The analysis, based on data from over 1,000 systematic sampling sites across Switzerland, reveals a significant impact of the Last Glacial Maximum (LGM) ice extent on the current distribution of groundwater amphipods. The findings highlight a pronounced species turnover and distinct spatial envelopes of species occurrences in zones that were formerly ice-covered, ice-free, or transitional.