Caracalla (198-217) AR Denarius (Silver, 2.38g, 19mm) Rome, 206.
Obv: ANTONINVS PIVS AVG Laureate and draped bust of Caracalla to right, seen from behind.
Rev: PONTIF TR P VIIII COS II Mars standing front, head to left, with right hand supporting shield set on ground and holding reversed spear in left.
Ref: RIC 83.