MACEDONIA, uncertain
c. 500 BCE

AR trihemitetartemorion (trihemiobol), 6 mm, 0.28 gm 
Obv: monkey squatting left
Rev: round shield or pellet within incuse square
Ref: "Uncertain Thraco-Macedonian Coins, Part II", Nomismatika Khronika (1998, Tzamalis), 67

This enigmatic series showing a monkey squatting either right or left with a round shield on the reverse, is the only Greek coinage of the classical period to depict such an animal. Monkeys are known to have been kept as house pets in antiquity, but its significance in this context is unknown.