I need help identifying this coin. I was told it is Roman, however it can also be anything else from that period.
According to the seller, the coin has around 23mm and weights 2.37g. Together with this coin, I also bought another Roman coin from the same seller, which I identified as 1/2 Maiorina from between 348 AD until 350 AD (https://en.numista.com/catalogue/pieces10601.html), if it helps.
These are photos of the unidentified coin:


The first two photos are of the back of the coin, where there is a drawing that it looks like a man throwing something (possibly a spear or trident) and standing on a platform. The last photo is of the front, where a head can be seen (possibly wearing a helmet) and an m-like sign on the top-left of the head (top-right of the image).
Thank you



