Reworked phosphoritic concretions from the base of the Diest Sands (Miocene) at Ramsel (Belgium) yield many magnificent crabs and molluscs in mould preservation. Two species of crabs are present, viz. Mursia lienharti (Bachmayer, 1961) and Tasadia carniolica (Bittner, 1884), Tasadia being a new genus. The palaeoecology of the decapod fauna is discussed and compared with Paratethyan occurrences. The age of the fauna in the concretions as indicated by the mollusc fauna is Middle Miocene, Hemmoorian, youngest Oxlundian. A similar fauna, also in reworked concretions, is known from the base of the Deurne Sands at Borgerhout (Antwerpen city area). A new coleoid cephalopod species, Spirulirostra baetensi sp. nov., is described. The European Spirulirostra and Spirulirostrina species are discussed.