I can definately eliminate Pearl dace they are much more cigar shaped. I'm quite sure its not Pimephales of any kind and especially not notatus. I've caught and kept many of these in many areas. That picture from the UMMZ is not a Pimephales either.
I can assure you the UMMZ fish is a Pimephales notatus there is no question about this...the fish is a juvenile female. There is absolutely no question on the identity of that fish. It actually is not even open for discussion as it is as described.
You can do the meritistic analysis yourself from that photo and it will firmly be P. notatus...
If you wish ask... Histrix to pull the fishes information and provide data on it as she can do so. I also would have no issue with asking to have the fish pulled and taking detailed measurements with photos myself and providing them.
Edit: I'M TOTALLY WRONG
I admit when I'm wrong and for all reading this please note I was totally wrong on this...Apparently a Spotfin shiner was mixed in the lot containing the collection of Bluntnosed and was mistakenly photographed as one....I normally take these collections as very accurate but in this case it was very much not accurate at all....Egg on face and I eat my above strongly worded post..