Zoroaster Wyville Thomson 1873

Thomson 1873: 154; For full synonymy see Mah (2007).

Diagnosis

Disc small. Disc and arms with imbricate skeleton. Carinal plates ridge-like. Primary spines present or absent on carinals, marginal plate series. Superambulacrals reduced. Internal buttress absent. Based on Mah (2007).

Comments

Zoroaster includes 20 living, and 2 fossil species. Living species are present in the Atlantic, Pacific and Indian Oceans, between 100–5000 m (Mah 2007). Relatively few characters distinguish between known Zoroaster species (e.g. H.L. Clark, 1920) and character variation is poorly understood for most species. Downey (1973) synonymized five Atlantic species with Zoroaster fulgens but commented that doing so created complications resulting from collapsed character distinctions within H.L. Clark’s (1920) identification key. Existing diagnoses for the Atlantic Zoroaster fulgen s do not clearly distinguish from Indian and Pacific species. Additional specimens have added to our understanding of character variation between and among species, but further revision, most likely with molecular data will be needed to fully clarify taxonomic boundaries for living Zoroaster species.