Possible Jurassic Wood-boring Bivalve

[old digger]

This specimen was found in the Harrison Lake area of southwestern British Columbia, in beds reliably dated late middle Jurassic (Callovian).  It appears to be a bivalve shell with two large protuberances emerging from it.  The wood-boring bivalves Pholadacea come to mind, but, since I have no record of anything like this from the area, and no experience with these forms, I welcome your comments and suggestions. 

[Wrangellian]

I'm having trouble interpreting the pic. Can you provide more, from different angles etc?

You might need a paper that describes the bivalves from there if you don't already have it (I don't, though I'm curious as I have some specimens from there and I couldn't hurt to have more info on them), maybe someone here can point you in the right direction.