Crinoids- Sea Lily. Feather stars Echinodermata Photos--live, preserved and fossils. Crinoid living cluster. MASS MORTALITY CRINOID CLUSTER.
Photos--live, preserved and fossils
Jimbacrinus bostockiPermian Age - 283 Million Years OldCundlego Formation, Gascoyne Junction, Western Australia Crinoids are known as "Sea Lilies" but are not plants at all. They are, in fact, small plankton-gathering animals that possess feathery structures on their arms to filter the plankton from seawater. They were anchored to the seabed or rocky substrate by a stalk that allowed them to sway back and forth in the changing currents like a tree in the wind. They are closely related to starfish and urchins, and exist where there are strong currents, such as intertidal areas or offshore channels, to bring lots of the plankton within their reach of their arms. Frozen in solid rock for over 280 million years, it takes the exquisite skill and dozens of hours to prepare and expose a multi specimen such as this. Measuring 12 x 7 inches, this specimen makes a very attractive display piece and exquisitely exhibits the natural beauty and symmetry of the ocean's creatures.
Crinoids are called "sea lilies," but despite their appearance, are animals rather than plants.
Their closest familiar relative is the modern starfish. They look like plants because the body skeleton, or calyx, generally grows on the end of a stem made of button-like discs. The stem is held on the sea floor by either a stony anchor or root-like arms.
The mouth, on top of the body, is surrounded by arms that sweep food into the mouth.
The body is made of five-sided calcareous plates that fit together like irregular bricks.
When the animal dies, the plates and discs tend to fall apart and sink to the sea floor.
Many of the limestone beds in Illinois are composed mostly of crinoid plates and discs. The complete calyx is a highly prized fossil.
Good ones are found in the limestone cliffs along the Mississippi River between Burlington, Iowa, and Alton.
Stems or separate stem discs are common throughout most of Illinois and are popularly called "Indian beads" or "fish bones." The oldest crinoids come from Ordovician rocks (490 to 443 million years ago). Some crinoids live today, mainly in deep parts of the ocean, but they are not nearly so common as in the past.