De Stompe grondwaterslak Avenionia roberti Boeters, 1967 na 69 jaar teruggevonden in het Jekerdal in Maastricht

Various attempts were made to recover Avenionia roberti Boeters 1967 from groundwater in the Jekerdal in Maastricht, province of Limburg. The snail had been found living there in 1944 and 1946 at the bottom of a (later filled-up) well. This time, groundwater was pumped out and sieved through seven old-fashioned, hand-operated pumps installed in the Jekerdal by gardeners and farmers. These attempts had no success. However, eventually some empty but recent shells of Avenionia roberti were recovered from sediment exhausted by a small, natural well discovered in the Jekerdal.