Early Classical period (480-450 BCE)
Zeus (or Poseidon?), from the sea off Cape Artemision, Greece, ca. 460-450 BCE.
A huge development from the stiff postures of the archaic (600-480 BCE) kouros to nude athletes, movement, more naturalistic poses, bronze materials and contrapposto (weight shift).
Other famous early classical sculptures: Myron’s Discus Thrower (ca. 450 BCE)
(Source: fransite.net)