Mediaster Stimpson, 1857

Mah, Christopher L., 2016, Deep-sea (> 1000 m) Goniasteridae (Valvatida; Asteroidea) from the North Pacific, including an overview of Sibogaster, Bathyceramaster n. gen. and three new species, Zootaxa 4175 (2), pp. 101-141 : 118

Mediaster Stimpson, 1857

Mediaster Stimpson 1857: 530 ; Perrier 1894: 377; Verrill 1899: 178; Fisher 1911: 196; Verrill 1914: 295; 1915: 108; Fisher 1919: 255; Macan 1938: 369; H. L. Clark 1946: 83; Bernasconi 1963: 11; Halpern 1970: 202; Clark & Downey 1992: 251. (as Mediaster )

Comments. Mediaster includes 18 nominal species ( A.M. Clark 1993, Mah 2015b) which occur in the Atlantic and Pacific Oceans and is among the earliest genera of starfishes described from the Pacific coast of North America ( Stimpson 1857). Fisher (1911) reviewed two species present from the North Pacific , M. aequalis and M. tenellus and discussed taxonomic relationships among Atlantic and Pacific species. Carey (1972) subsequently discovered “ Mediaster elegans ” (= Bathyceramaster careyi n. sp) from deep-sea settings off the coast of Oregon.

Fisher (1911) pointed out the absence of the stellate radiating base, a defining characteristic of the genus, in the tropical East Pacific “ Mediaster elegans " Ludwig 1905 but did not undertake a revision of the group. During the course of this investigation both “ Mediaster elegans ” Ludwig 1905 and the species described by Carey (1972) as “ M. elegans ” were both found to be lacking the diagnostic synapomorphy for Mediaster and have since been reassigned to the new genus Bathyceramaster n. gen. (as above).