Question

Write some features of crinoidea??

Answer 1

$\textbf{Crinoidea..}$

》Body is star shaped but the central disc remain attached to substratum.

》Mouth and anus are present on oral surface.

》Arms are branched and bearing pinnules.

》Spines, Pedicillariae, Darmal branchiae are absent.

》They are sessile animals.

》 Their larva is Doliolaia.

eg➡ Antedon--> Sea lily or feather star.

Hope it helps u✌

Answer 2

$\huge{HEY!!}$
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✴Crinoidea is a plural form of an organism named crinoid.

✴The word crinoidea is arised from two words which are "krinon" and "eidos".

✴The word krinon means "Lily" and "eidos" means "formation".

✴Nearly 600 to 700 species of crinoidare still alive in the today's world.

✴It is believed that the crinoid were closer to extinction approximately 250 years ago during the time of Permian Period.