This is a very nice Eucalyptocrinus crassus fossil crinoid calyx from the famous St. Paul, Indiana locality. This is an upper Silurian deposit. This calyx is nicely inflated and not crushed at all. There is also a brachiopod on the top of the tegmen (see the last pic). This fossil is ~430 million years old!
Crinoids are echinoderms, related to starfish and sand dollars. They are often called sea lilies and resemble underwater flowers, but are actually animals. This calyx is just the "bulb" of the animal. There would have also been a long stem and arms to grab at food.