Odontasteridae Verrill 1899

ODONTASTERIDAE Verrill, 1899

Comments

The Odontasteridae currently includes six genera, which all occur in the Southern Hemisphere, primarily at high-latitudes with some species of Odontaster Verrill, 1880 exceptionally present in the Northern Hemisphere in deep-water settings from the North Atlantic and North Pacific (Fisher 1911; Clark & Downey 1992) and one species of Hoplaster Perrier in Milne-Edwards, 1882 from the Atlantic (Clark & Downey 1992). The most recent genus and species within the Odontasteridae, Diabocilla clarki McKnight, 2006 was described from New Zealand waters (McKnight 2006).

The Odontasteridae has largely been supported as monophyletic by three-gene molecular data (Mah & Foltz 2011b) relative to other families within the Valvatida. The Chaetasteridae Sladen, 1889 was supported as the sister branch to the Odontasteridae. Genera within the Odontasteridae have shown superficial resemblance with taxa in the Goniasteridae and the Astropectinidae Gray, 1840 owing to its spiny, paxillate abactinal and marginal plates suggesting broader affinities. Most genera are identified by a distinctive hyaline recurved spine or spines on each interradial oral plate. Two genera, Hoplaster and Diabocilla lack these spines and have not been tested with molecular phylogenetic data.

Diagnosis

Body shape pentagonal to strongly stellate. Abactinal plates variably convex and flat ranging to paxillate or tabulate with surface covered by accessories, variably granules or spinelets. Papulae single, limited to abactinal surface. No enlarged spines. Marginal plates blocky, quadrate in shape; appearing variably as a wide distinct border around body periphery to a narrow, lateral-facing series present along a crenulate actinolateral-ridge. Marginal plate accessories, ranging from granules to spinelets, present in some species in high density, abundance. Actinal plates in chevron-like formation, intermediate areas variable in size. Actinal plate accessories variably granules to spinelets. Spines on adambulacral plates in most with transverse series. No superambulacral plates. Most genera with one or two large hyaline-tipped recurved spine or spines on the oral plate. These spines absent in Hoplaster and Diabocilla.