Watch List notes:

Moesia Superior, Viminacium. Gordian III. A.D. 238-244. Æ as (19.0 mm, 3.26 g, 7 h). RY 2 = A.D. 240/1. IMP CAES M ANT GORDIANVS AVG, laureate head right, draped left shoulder / PMS COL VIM, Moesia standing between bull and lion, AN II in exergue. Martin 1.14 var (bust type); AMNG 78 var; Varbanov 114 var. Fine. Rare variety. 

Ex George Spradling collection. 

None of the major references list this bust type.