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Valvadita

* conspicuous marginal ossicles

Asteropseidae

* small surface plates covered by   smooth tough skin.
* arms relatively short

Goniasteridae

* numerous large plates on upper   surface

Ophidiasteridae

* Small disc
* Long arms, almost round in cross-section.

Spinulosida

* Pedicilariae rare
* Marginal plates small &    inconspicuous.
* Spines in groups on upper    surface

Asterinidae

* small plates without major gaps

Echinasteridae

* rounded plates with gaps between
* numerous spinelets on plates
* lack large maginal plates
* small disc
* 5 long arms almost round in cross-section

Paxillosida

Astropectinidae

* tube feet with pointed tips
* pointed arms
* prominent rows of spines on arm margins

Forcipulatida

Asteriidae

* lack large marginal plates
* numerous pedicellaria on upper   surface
* 4 rows of tube feet