Abstract. In the second half of the nineteenth century a few Italian radiolarists, including Dante Pantanelli and Senofonte Squinabol, made substantial contributions to the taxonomic study of radiolarians and their utilization in dating Mesozoic rocks. This time interval was very important in the history of science in general, and biology in particular, with numerous scientific expeditions collecting a wealth of biological and sedimentary material from the oceans that took decades to be described and analysed. One of the most famous examples is the Report of the Challenger Expedition, which included a thorough study of radiolarians by Ernst Haeckel which became the basis of radiolarian classification. Haeckel was one of the foremost promoters of the largest cultural revolution of his epoch: Darwinism. He, together with a long list of eminent scientists, used comparative anatomy and embryology to provide evidence of the theory of evolution through natural selection. One of his students, Anton Dohrn, also a fervent Darwinist, founded one of the oldest independent marine biology stations in the world: the Statione Zoologica in Naples. It was here that at the beginning of the twentieth century another eminent Italian radiolarist, Paolo Enriques, worked for many years to revise and improve Haeckel’s classification scheme of radiolarians, although he died before it was completed or published.