Rubber pieces in oil

[pilotyoung]

I drained the oil in my AeroVee engine Tuesday and found little pieces of rubber in the oil screen. I have the mini-sump kit on my engine. I am wondering if anyone has any idea what the pieces of rubber could be. I am including a picture of the pieces on a white paper towel.

[bvolcko38]

The only thing I can think of is possibly parts of a damaged O ring.

[BRS]

Looks like gasket material. Perhaps from the sump cover?

[Raluttio]

How many hours on the engine? If it is still in the double digits then my first thought is a couple big chunks of excess gasket maker broke loose. The only rubber in the engine is the six o-rings on the case studs - this doesn't look like one of those though.

[pilotyoung]

The engine has over 400 hours on it.