What is "scyphocrinus"

Scyphocrinus, is an extinct genus of crinoids. Species belonging to this genus live in the Silurian and Devonian periods (from 443.4 to 358.9 Ma).

The crinoid genus Camarocrinus have been considered by some authors the bulbous distal end of the stem of Scyphocrinus, having the function of a root and fixing the crinoid to the sea button.