I found these small, pale larvae in the very flaky, rotten core of a live maple tree. They had gravitated to the areas with more moisture. Superficially they resemble Tenebrio*nidae but the anal area has details I've never seen, nor do I recall ever having seen larvae that assumed this J-shaped posture. I hope these details will make an ID possible but in case not, I am intent on rearing these guys so we have an adult to ID.