Plastic Stuck Between Chain and Wheel

[anips]

So I ran over some plastic and it got stuck between my wheel and chain.  I loosened the axle bolt and got the plastic out but noticed a circular black thing that's fused to the plastic that kinda looks like an o-ring?  I'm not sure if it is or if it's just the plastic that kinda got melted and dirty and then hardened to make it seem like it is an o-ring. I can't tell by feel so am wondering if anyone knows if there is supposed to be a rubber o-ring between the wheel and chain and if so what is the part number so I can replace it.  Here is a picture of it and also where I took it out from. And if there's anything else I need to worry about please let me know.  Thanks!
 
 

[i28]

 (I could be wrong but...) it looks like the plastic just melted in a circular pattern because of the friction at the place it was stuck. 
this should give you a visual idea of the parts in that area:
https://www.shopyamaha.com/parts-catalog/parts/street-mcy#/Yamaha/FZ07_-_FZ07FCR_-_2015/REAR_WHEEL
it looks too big to be one of the seals ([HASH]3 or [HASH]13 from the diagram... unless there's another part that is not pictured in that schematic but I didn't find anything else) 

[anips]

Thanks! I took a closer look and it was actually a ziplock bag. The hard circular pattern was the part where you snap together the bag to seal it which is why it felt like an o-ring! Crisis averted, and chain slack tightened and oil changed since I had my tools out lol. Damn litterbugs!
 
 

[rick]

Better to have it get caught there than melted onto your exhaust where it would burn and stink for weeks to say nothing of leaving a black mess.