Coin Identification help

[nikmane]

Hi all, I bought a small lot of coins.
I can not identify this, can you help me?
Thank's

Diameter: 16.30 mm
Thickness: 0.87 mm
Weight: 1.14 g

 

[Mackaydon]

Roman
Don......

 

[A2coins]

looks really old looks like a lawn mower got it or fertalizer if it was in the ground

 

[Mackaydon]

I realize it's an old thread.
The reverse can be described as 'two soldiers holding spears and shields, military standard between them".
This image is also described as 'gloria exercitvs'.
The obverse looks like Constantine or Constans.
The age would be between AD 336 and 342 IMO.
Don in SoCal.