Antoninus Pius and Marcus Aurelius, as Caesar. AE Sestertius. 
140-144 AD. 

ANTONINVS AVG PI-VS P P TR P COS III, laureate head of Antoninus Pius 
right, slight drapery on left shoulder.
AVRELIVS CAESAR AVG PII F COS, S C in exergue, bare-headed,
draped bust of Marcus Aurelius right. 

RIC III 1212; Cohen 34. 

Courtesy of Stack's Bowers and Ponterio 
Sale 173 January 2013, lot 6167, sold for $450