''Thromidia gigas'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

starfish Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish ...

in the family

Mithrodiidae The Mithrodiidae is a family of starfish in the order Valvatida. Members of this family are big to huge tropical sea stars with 5 arms, rounded in cross-section. List of genera and species * Genus '' Mithrodia'' Gray, 1840 ** '' Mithrodia br ...

in the order

Valvatida The Valvatida are an order of starfish in the class Asteroidea, which contains 695 species in 172 genera in 17 families. Description The order encompasses both tiny species, which are only a few millimetres in diameter, like those in the genu ...

discovered by Mortensen in 1935. It lives off the coast of eastern

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

and southern

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

. This species is probably the largest

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 ...

in terms of bulk, and may exceed 13 lbs.

Reference

Mithrodiidae {{Improve categories, date=January 2022