Goniasteridae constitute the largest family of sea stars, included in the order Valvatida. They are mostly deep-dwelling species, but the family also include several colorful shallow tropical species.
Spatangus is a genus of heart urchins in the Spatangidae family. The genus is synonymous with the previously recognised genera Prospatangus Lambert, 1902 and Spatagus. There are nine recognised species. The type species is Spatangus purpureus Müller, 1776 by subsequent designation.
The Oreasteridae are a family of sea stars in the class Asteroidea.
Ammotrophus arachnoides is a species of sand dollar of the family Arachnoididea. Their external skeleton, known as a test, is covered with spines. It belongs to the genus Ammotrophus and lives in the sea off southern Australia. Ammotrophus arachnoides was first scientifically described in 1938 by Hubert Clark.
Ammotrophus platyterus is a species of sand dollar of the family Clypeasteridae. Their armour is covered with spines. It came from the genus Ammotrophus and lives in the sea. Ammotrophus platyterus was first scientifically described in 1928 by Hubert Clark.
Asthenosoma is a genus of sea urchins in the family Echinothuriidae. Their spines are covered with harmful venom capsules.
Ophiactis is a genus of brittle stars (Ophiuroidea).
Araeosoma is a genus of deep-sea sea urchins in the family Echinothuriidae.
Mediaster is a genus of starfish in the family Goniasteridae. It was circumscribed in 1857 by William Stimpson for M. aequalis, the genus's type species. Its junior synonym is the genus Isaster, which was circumscribed in 1894 by Addison Emery Verrill for the species now known as M. bairdi. Verrill himself synonymized the two genus names in 1899.
Aporometridae is a monotypic family of crinoids, the only genus being Aporometra, which contains three species, all endemic to the seas around Australia.
Fibularia is a genus of echinoderms belonging to the family Fibulariidae. The genus has almost a cosmopolitan distribution.
Stylocidaris is a genus of echinoderms belonging to the family Cidaridae.
Ophiura is a genus of echinoderms belonging to the family Ophiuridae.
Echinocyamus is a genus of echinoderms belonging to the family Fibulariidae.
Cassidulus is a genus of echinoderms belonging to the family Cassidulidae.
Phyllacanthus is a genus of echinoderms belonging to the family Cidaridae.
Ophiarachnella is a genus of echinoderms belonging to the family Ophiodermatidae.
Ophionereis is a genus of echinoderms belonging to the family Ophionereididae.
Plagiobrissus is a genus of echinoderms belonging to the family Brissidae.
Macrophiothrix is a genus of brittle stars.
