Caracalla, AE proto-contortionate sestertius, after 210 AD. 30mm, 25,68g.

M AVREL ANTONINVS PIVS AVG, laureate bust right, slight drapery
on left shoulder. 
PONTIF TR P XIII COS III, S-C, Mars in military dress,
advancing left, holding branch and trophy. 

Cf RIC 450b for type, unlisted as proto-contortionate. 

Contributed by Dr. Hubert Lanz, auction November 2000, 
Added July 2011.