A mythical giant who surported heaven on his shoulders?

Often mistakenly thought to be Atlas, but Atlas actually supports the heavens, not the earth. Though he is seen in sculptures supporting a globe, this has no basis in any Greek mythology. I cannot recall ever hearing the world itself being supported by something or someone, other than perhaps Terry Pratchett's Discworld series of books, where Discworld, a large, flattened disc of land and water, is supported by four elephants on the back of a giant turtle named Great A'Tuin. Yes, Atlas was the brother of Prometheus and Epimetheus, son of Iapetus and Clymene.