Marcus Aurelius (161-180) AR Denarius (Silver, 2.95g, 17mm) Rome, 163-164.
Obv: ANTONINVS AVG-ARMENIACVS, bare head of Marcus right
Rev: P M TR P XVIII-IMP II COS III, Mars standing facing in full military dress, helmeted head right, reversed spear in right hand, resting left hand on shield.
Ref: RIC III 91