It’s called Global Thermonuclear War “What the hell did I find during my oil change?”

I found these pieces of metal whilst underneath the Tahoe looking up into the engine oil return after I had removed the filter. I grabbed it with a very long pair of pliers, breaking it as I removed it from the engine inlet. They appear to have been a single, circular piece at one time. They are also very heat-affected, and are quite brittle.

So what do you think? Piece of a crappy old oil filter that came loose? Part of a lash adjuster or valve-stem seal? Something far more heinous?

Vehicle is a 5.3 Tahoe with over 200k miles, and no, I have no clue what they are. Truck runs fine though...for now...