Mazon Creek bivalve siphon?

[connorp]

I just received this nice Aviculopecten bivalve from Mazon Creek today. What catches my eye is the thing extending from the top of the shell. It almost looks like it could be the siphon protruding outwards. I haven't seen a similar specimen before. Any thoughts?

[Wrangellian]

I'm not sure that Pectenids had any sort of siphon that extended far beyond the shell. Certainly the angle looks wrong...

But I don't know what it could be. Any other ideas?

[Nimravis]

I do not think that it has anything to do with the pecten itself. Rob @RCFossils What do you say?

[caldigger]

I don't think pectens have siphons. 

It seems there may have been two things coincidentally overlayed on top of eachother.

[Mark Kmiecik]

They do have a foot, but only about 1/10 that length. This is also located at almost 180 degrees away from the correct anatomical position of the foot.

[Fossildude19]

Possibly the remains of the bivalves' burrow? 

[Tidgy's Dad]

I think the shell is lying on top of a piece of plant matter. 

[RCFossils]

I would agree it is plant matter.

[connorp]

Upon closer exam under a microscope, it does look like poorly preserved plant material. Thanks all.