Caracalla, AE18 of Carrhae, Mesopotamia.

Obv: AVT K M A(NTWNEINOC), laureate head right
Rev: KARKO MHTRPOL, Crescent, horns upwards with pendent fillets, placed 
upon base; eight-pointed star between the horns.

BMC 10.

With permission of Roma Numismatics, Sep. 2010
(Thanks to Kurt E. of the Forvm Ancient Coins for the attribution)