Crinoid Stems
Crinoids belong to the animal kingdom and are related to Star Fish.
A growing crinoid looks very plant like, a long stalk attached to the ocean
floor with a flower like top. They are commonly called Sea Lilies.
This piece of limestone contains numerous crinoid stems, the disks that
the crinoid stalk is composed of. Note the 5 sided "star" in the center
of each disk - Star Fish have five arms.
Period: Middle Ordovician, 450,000,000 years
Location: Ottawa Valley
