Jatayu is the youngest son of Aruṇa. His brother, Sampaati, is a demi-god who has the form of an eagle and was an old friend of Dasharatha.
When Jatayu sees Ravana abducting Sita, he tries to rescue Sita from Ravana . Jatayu fought valiantly with Ravana, but as he was very old Ravana soon got the better of him. As Rama and Lakshmana chanced upon the stricken and dying Jatayu in their search for Sita, he informs them of the fight between him and Ravana and tells them that he had gone south.
Jatayu and his brother Sampaati, when young, used to compete as to who could fly higher. On one such instance, Jatayu flew so high that he was about to get seared by the sun's flames. Sampati saved his brother by spreading his own wings and thus shielding Jatayu from the hot flames. In the process, Sampaati himself got injured and lost his wings. As a result, Sampaati lived wingless for the rest of his life.
While Jatayu was wounded and lying on the ground when Lord Rama arrived, Lord Rama sensed the end result and decided that Jatayu gets moksha. Lord Rama then slammed an arrow into the ground so as to call all seven sacred rivers, called teertha. Six rivers waters arrived, one river water failing to obey Lord Rama's call. Since Lord Rama was himself an incarnation of Lord Vishnu, He forced the Gaya teertha to arrive at the spot.
ALSO READ | Kaikeyi: An elusive and contentious character of epic ‘Ramayana’