Crinoid fossils are most commonly found in limestone deposits that were once ancient seabeds. These fossils often consist of the stalk or column, the most durable part of the crinoid’s anatomy.

It forms small round or ellipitical patches within the limestone. American Indians used chert for tools and weapons. Crinoids are marine animals that look like flowers. It has a long stem or stalk and ...

It was not so terribly long ago; that the original planktonic mix gave birth to some zillion critters with the advantage of ...

The Supai Group, consisting of deep-red siltstone, limestone, and sandstone, is 600 to 700 ft thick. Within these layers are marine fossils, including brachiopods, corals, crinoids, and gastropods.