UPDATE: I originally labeled this as a spiny snail but after more research it is a spiny brachiopod. The descriptions have been now fixed.
Here is a Devonian brachiopod a friend found on his visit to Louisville. It has 5 spines visible and is around 2 cm in diameter. It is sharing rock with several brachiopods and a horn coral.
It appears to be a Productella spinulicosta (Hall, 1867) in the Jeffersonville Limestone. Might also be known as Spinulicosta spinulicosta (how original).
According to this Kentucky Geological Survey page, the Jeffersonville Limestone is similar to the Onondaga Limestone of New York and the Grand Tower of Illinois (Savage, 1931).