Medusa part of their religion. Medusa was beheaded by the hero Perseus, who thereafter used her head, which retained its ability to turn onlookers to stone, as a weapon until he gave it to the goddess Athena to place on her shield. In classical antiquity the image of the head of Medusa appeared in the evil-averting device known as the "Gorgoneion". The three Gorgon sisters—Medusa, Stheno, and Euryale—were all children of the ancient marine deities Phorcys (or "Phorkys") and his sister Ceto (or "Keto"), chthonic monsters from an archaic world. Their genealogy is shared with other sisters, the Graeae, as in
Pierides (mythology) Pierides (mythology) In Greek mythology, the Pierides (Ancient Greek: Πιερίδες) or Emathides (Ἠμαθίδες) were the nine sisters who defied the Muses in a contest of song and, having been defeated, were turned into birds. The Muses themselves are sometimes called by this name. They were the daughters of Pierus, king of Emathia in Macedon, by Antiope of Pieria or Euippe of Paionia. The sisters were also called Emathides, named after their paternal uncle Emathus. In Ovid's "Metamorphoses", Urania, one of the Muses recounts their contest with the Pierides to Athena in the following excerpts:"So spoke the Muse. And now was