Download Crinoids- Sea Lily

Crinoids- Sea Lily
Feather stars
Echinodermata
Photos--live, preserved and fossils
Crinoid living
cluster
MASS MORTALITY CRINOID
CLUSTER
Jimbacrinus bostocki
Permian Age - 283 Million Years Old
Cundlego 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.
Crinoid shrimp
Master mimics
Protective camo’!!!
Crinoids (Cry'noyds)
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.
Crinoid disks
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.