Cladaster Verrill, 1899

Mah, Christopher L., 2011, Taxonomy of high-latitude Goniasteridae (Subantarctic & Antarctic): one new genus, and three new species with an overview and key to taxa, Zootaxa 2759, pp. 1-48 : 19

Cladaster Verrill, 1899

Verrill, 1899: 175; Fisher, 1911: 221; Bernasconi, 1963: 13; 1964: 255; Halpern, 1970b: 179; Clark & Downey, 1992: 238; Clark, 1993: 251.

Diagnosis. Body weakly stellate. Abactinal plates low tabulate with weakly to strongly expressed fasciolar channels. Hemispherical granules present on abactinal, marginal, and actinal plate surface which are deciduous on preserved specimens. Large, spatulate type pedicellariae present. Furrow spines, two, thickened and oval in crosssection. Large, thick subambulacral spine present in addition to furrow spine

Comments. Cladaster includes five nominal species, some of which are separated by either continuous character differences (i.e., number of superomarginals vary between species, number of granules per plate surface, relative thickness of furrow spines) or relatively few, discrete character differences. Clark and Downey (1992) and McKnight (2006) have also commented on how ontogenetic characters, such as specimen size and number of abutting superomarginal plates have been the primary means of distinguishing species. Factors such as the wide geographic separation of known species and paucity of specimens have encouraged retention of established Cladaster species, in spite of overlapping characters and discrete taxonomic boundaries.