Most people would include the greater part of the fourth century (up to 323 bc, with the death of Alexander) into the classical period, and I agree with them. It is yet useful to discuss the 4th century on it's own. What we find is that the development during the earlier period continues, but with change sneaking around the corner.
This piece is called the Antikythera bronze (due to it's find spot in the sea close to the island with the same name, and you might reckon that the Artimisian Poseidon was found under similar circumstances), dates from ca 350 BC and the stance is typical for the period. The piece is normally interpreted as Perseus, who should hold Medusa's head in his right hand and a sword in his left, but a more recent theory argue that this is Paris with who hold the apple of strife (which led to the siege of Troy).
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