In Greek mythology, Eurypylus (/jʊəˈrɪpɪləs/; Ancient Greek: Εὐρύπυλος Eurypylos) was a son of Poseidon and the Pleiad Celaeno, and together with his brother Lycus,[1] they ruled over the Fortunate Islands. Others state that Eurypylus was a king of Cyrene, and note that the brothers were also referred to as Eurytus and Lycaon.[2] Eurypylus married Sterope, a daughter of Helios and had two sons, Lycaon and Leucippus.[3][4] Triton assumed his shape when he encountered the Argonauts in Libya.[5][6] This Eurypylus must not be confused with another son of Poseidon named Eurypylus, king of Cos.