Severus Alexander. AE. Nisibis, Mesopotamia. 

AV KAI MAR CE ALEXANDROC, radiate head right
CEP KOLO NECIBI MHTPO, turreted and  draped bust of Tyche
 right, ram leaping right above, star to right. 

SNG Cop 235; Mionnet 5, 170v; BMC 4v. 
(Mionnet and BMC cite laureate head right)

With permission of Roma Numismatics, November, 2009