Thank you. Besides lots of turtle shell and unidentifiable fragments I also got one alligator scute and a couple rodent vertebrae and a few coprolite "poo" probably alligator.
Are you sure the tooth is whole? There is no tooth the horse's mouth with a edge like that. Maybe it is broken in half, and the edge was a result of the break.
I think you have a rare find. That's a un-erupted juvenile horse tooth.
In english, it's a tooth that was IN the jaw of the horse when it died; the tooth never finished developing. The tooth was never used, that's why there is no visible 'chewing' surface.
If you can imagine a baby horse, that still had it's first teeth. Underneath it's 'baby' teeth, the adult teeth are growing. That's what I think you have. One sign of that is the 'scrunchy' look the enamel makes at the bottom of the tooth.