Pelmatozoa

Blastoidea from Haeckel's " Art Forms of Nature "

The Pelmatozoen ( Pelmatozoa AltGr. Πέλμα, Sole ' and ζώα, animals ') are a sub-tribe of the echinoderms. All Pelmatozoen have the time or only in their youth, a sessile lifestyle and sit, usually by a stalk, which can vary in length, with its mouth opposite side of the seabed on. They are therefore also called primary stalked echinoderms. There are about 620 extant species, all belonging to the class of sea lilies and feather stars ( Crinoidea ). About 3900 species have become extinct. They belong to the buds radiators ( Blastoidea ), the bag radiators ( Cystoidea ) and the Edrioasteroidea.

Pelmatozoen are probably the original form of all echinoderms. The body of the Pelmatozoen is generally cup-shaped and surrounded at its top by numerous, mostly feathered arms. Mouth and anus lie with them on the same side of the body.

In Paleozoic and early Mesozoic the Pelmatozoen were so numerous that from their fossilized limestone slabs and stem members all limestone formations were formed in the mountains.

Classes

• † buds radiator ( Blastoidea )
• † bag radiator ( Cystoidea )
• † Edrioasteroidea
• Sea lilies and feather stars ( Crinoidea )