Eucalyptocrinites sp. scale in cms CLASS - Crinoidea ORDER - Monobathrida FAMILY - Eucalyptocrinitidae GENUS/SPECIES - Eucalyptocrinites sp. ROCK UNIT - Waldron Shale AGE - Silurian (425 million years old) LOCALITY - Waldron, Indiana, USA Crinoids attached to the sea floor by many different methods. Some coiled their stems or attachment arms (cirri) around other stationery sea floor objects. Others used different styles of specialized anchoring structures or "holdfasts", including those resembling grappling hooks, weighted globes and cemented discs. This root-like holdfast is common in marine shales and must have been well suited for life on soft mud bottoms. PRI 42173