Our fossil club gained access to a quarry in Central Iowa. The quarry exposes most of the Cedar Valley Formation, so I can not break it down any farther than this, as the fossil was found in a pile of rubble. When I found this specimen, I showed it to 4 different individuals, all of whom called it placoderm "tooth". My research upon arriving home could not find placoderm examples resembling this find. So I am leaning towards a shark tooth??????? Your assistance is appreciated to helping me ID this: