This might be silly but I'd love to hear someone's thoughts on it. I found this cowrie/puka shell in a very rural creek in Eastern KY (Pike county). At the time I just thought there must be freshwater cowries, like the clam shells that litter that river too. I've since found out that isn't true. It's very matte and somewhat bone-y to the touch.

I'm not sure how to tell if it's a fossil or just an old shell! I've been looking into it and cowries don't line up with oceanic history of KY as far as I know. I know Native Americans used cowries for trading and decor so it could have traveled that way, maybe? I just find it really odd that this shell would be there at all. I don't recall if there were more like this one. I also can't find anything that looks similar in records of fossils found in KY before. Lots of mollusk in that area, none like this.

It sure does look a lot like the 3rd pic, which I found with this caption:

"Trona leporina calhounensis Dolin, 1991, from the Miocene Chipola Formation of Florida. The dorsal part of the fossil is missing to reveal the inner whorls of the juvenile shell."

It's also possible it fell off of some kid's puka shell necklace.

Well done even recognizing that it was out of place, Alina! And as Scott said, it appears you have already done a lot of the research to solve this little enigma. Good job again!
As you mentioned, one can think of many scenarios about how this shell ended up in that creek but it's the little hole on the bottom side that makes me think a Native American association is most likely.
The shell native to the east coast of the US that was used as money, or 'wampum', was the now extinct Marginella shell. It was also called 'Roanoke' by the NA and was usually drilled thru the middle from the top to bottom. The Cowrie shell was used as “wampum” to the natives of Africa, and in the 18th century strands of Cowrie were brought to the US by Europeans as trade goods. That little hole on the bottom is one way they would 'drill' the shell to use as a bead.

Check out this link and see what you think,
https://www.mountvernon.org/preservation/archaeology/archaeology-online/object/1...

Given your locality, it would not be the least bit surprising if there was a NA campsite along the creek somewhere. Keep your eye out for some stone artifacts and Happy Hunting.