Phormosomatidae is a family of
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 sea ...
s belonging to the order
Echinothurioida
The Echinothurioida are an order of sea urchins in the class Echinoidea. Echinothurioids are distinguished from other sea urchins by the combination of a flexible test and hollow spines. The membrane around the mouth contains only simple plates, ...
.
Genera:
* ''
Hemiphormosoma''
Mortensen, 1934
* ''
Paraphormosoma''
Mortensen, 1934
* ''
Phormosoma''
Thomson, 1872
References
Echinothurioida
Echinoderm families
{{echinoidea-stub