Public aquaria have offered a novel opportunity to study large (sometimes over 2 m in body length) aquatic vertebrates that are difficult to observe in the wild or maintain in captivity at the university laboratory. The present study describes three paleontological studies of elasmobranchs that were being conducted at the Okinawa Churaumi Aquarium. These studies involved: 1) the evolutionary origin of viviparity, 2) developmental process of elasmobranch embryos, and 3) the reconstruction of paleoecology of the elasmobranch fossils using a stable isotope. Further involvement of aquaria into research would provide a broader impact on biological science, including paleontology.