I normally would agree(since I'm not an expert what so ever), but the "A" in the middle is actually a triangle. I'm not an expert in either Roman or Greek coins, all I know is the Greek alphabets fourth "letter" is a triangle.
Some history: The coin shows the deity of the longest river in Greece, the Acheloos (anglicised from the Greek Αχελωος). This is the head of a mature, heavily bearded man, with two long, straight, dangerous-looking horns sticking out over his brow.This coin came from the town of Oiniadai, which gives its name to a modern Greek municipality; but the cult of the deity Acheloos was widespread.
Source:River Gods on Ancient Coins
Don.....
PS: The obverse is probably the head of Zeus.