What Do Crinoids Look Like?

Crinoids can very basically be described as upside-down starfish with a stems. The stem of a crinoid extends down from what would be the top of a starfish, leaving the mouth of the organism opening skyward, with the arms splayed out. However, crinoid arms look articulated and feathery.

When did crinoids go extinct?

Crinoids came close to extinction toward the end of the Permian Period, about 252 million years ago.

Are there still crinoids?

Approximately 625 species of crinoids still survive today. They are the descendants of the crinoids which survived the mass extinction at the end of the Permian. It is estimated that over 6000 species of crinoids have lived on the Earth.