Crinozoa is a subphylum of mostly
sessile
Sessility, or sessile, may refer to:
* Sessility (motility), organisms which are not able to move about
* Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant
* Sessility (medicine), tumors and polyps that ...
echinoderm
An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the s ...
s, of which the
crinoid
Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are ...
s, or sea lilies, are the only
extant members. Crinozoans have an extremely extensive fossil history, which may or may not extend into the Precambrian (provided the enigmatic
Ediacaran ''
Arkarua'' can be positively identified as an edrioasteroid).
Classes within Crinozoa
The classes currently contained within Crinozoa include Crinoidea,
Cystoidea,
Edrioasteroidea, and
Rhombifera.
See also
*
List of echinoderm orders
This List of echinoderm orders concerns the various classes and orders into which taxonomists categorize the roughly 7000 extant species as well as the extinct species of the exclusively marine phylum Echinodermata.
Subphylum Crinozoa
C ...
*
Blastoid
Blastoids (class Blastoidea) are an extinct type of stemmed echinoderm, often referred to as sea buds. They first appear, along with many other echinoderm classes, in the Ordovician period, and reached their greatest diversity in the Mississ ...
s, superficially similar-appearing echinoderms that belong to a different echinoderm subphylum.
References
Animal subphyla
Paleozoic invertebrates
Extant Cambrian first appearances
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