According to guide page, range of angustatus is "(e. US (MA-IL-FL)" vs subspinosus which has much wider distribution,ae."(e. NA (QC-FL to MN-TX)" which also corresponds with BG submissions having no angustatus west of the Mississippi River. So in accordance with all that M subspinosus seems much more likely than M angustatus here in Missouri.

there is too much overlap. Do not use BG records in making species-level determination. The morphologic features are, I believe, on the underside. I am not saying your ID is wrong, but I feel you have not satisfactorily confirmed your ID.

I don't doubt your words and respect your knowledge, because of that I will move to genus, but for what it's worth, I just went through the entire field of submissions for this species and if I counted right there are 29 separate submissions , 3 or 4 from Canada, all the rest from eastern US. A couple have genitalia shots. Several were ID'd only via the images by well known BG beetle editors.The rest were ID'd only by amateur contributors like myself. What I don't understand is if all those were accepted without hesitation why is mine being questioned when it is one of the very few that is out of range of angulatus, again, according to information on INFO page. Do we need to move a bunch of these to genus level?I think I kept this particular beetle and if so I will try to get an underside shot that may or may not help me get him to species.