OLogy Cards > Crinoids

Crinoids

Next time you scuba dive into the depths of the ocean, keep an eye out for crinoids. These creatures look like flowering plants from a garden, but as their "petals" wave through the water, they catch food as it passes. These animals have been living in Earth's oceans for over 500 million years. And some types are still alive today!

Stats

Stumper

Most of the crinoids' body is made of:

leaves

calcium carbonate

skin

Correct!

Crinoids may look like plants, but they do have a skeleton that is made of calcium carbonate pieces called ossicles. They hold its muscles and ligaments together. Calcium carbonate is also the main ingredient in limestone.

Stumper

Which creature is very closely related to crinoids?

sea star

mud puppy

great white shark

Correct!

Crinoids are members of the phylum Echinodermata. Sea stars, sea urchins, and sand dollars are also members of the echinoderm group.

Fact or Fiction

Crinoids swim from place to place in search of food all of the time.

Fact

Fiction

Crinoids don't have to travel to find food because they are perfectly built for snacking on plankton and tiny creatures that drift by them.

Fact or Fiction

Crinoids go to the bathroom through a body part called the anal pyramid.

Fact

Fiction

Fact

Like most living creatures, crinoids have to poop. As unbelievable and yucky as it sounds, it's true. And believe it or not, the crinoids' mouth is right next to its other end!

Image credits: main image, courtesy of AMNH, Department of Library Services 10260.

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