Pillsburiaster micropeltus ( Fisher 1906 ) Mah, 2024

Mah, Christopher L., 2024, New genera and species of deep-sea Goniasteridae (Asteroidea) from the North Pacific, Zootaxa 5543 (4), pp. 451-500 : 479

Pillsburiaster micropeltus ( Fisher 1906) nov. comb.

FIGURE 9A–D

Tosia micropelta Fisher 1906: 1006 .

Peltaster micropeltus Fisher 1911: 205 ; A.M. Clark 1993: 269.

Pillsburiaster maini McKnight 1973 new synonymy

Diagnosis

Body stellate (R/r=1.93), interradial arcs weakly curved, arms triangular, tips blunt.

Abactinal plate round to irregularly polygonal, each covered by coarse, round granules, 1 to 4, mostly 2 to 3. Pedicellariae, small upright, spoon-shaped valves similar in size to adjacent granules. Superomarginals and inferomarginals 26 from armtip to armtip (13 per side) each with a distinct naked bald spot on the abactinal and lateral surface covered by granules. Spatulate pedicellariae present on proximal plates. Inferomarginals covered by granules with a similar bald spot on the actinal face-smaller in size than the corresponding superomarginal plate. Terminal plate large with a thimble-shaped tubercle. Actinal plates irregular, quadrate to hexagonal, covered by round granules. Weakly developed fasciolar grooves. Furrow spines, blunt tipped, 5 to 6 with subambulacrals in two series, set off from furrow spines, each composed of cylindrical spinelets, 3 to 4 per row, close-set. Mouth plates with 10 furrow spinelets, surface with granules similar to subambulacral spinelets on adambulacral plates.

Comment

USNM 21164, the holotype of Tosia micropelta Fisher 1906 possesses the coarse, round, clustered, abactinal granulation diagnostic of Pillsburiaster Halpern 1970 rather than Peltaster Verrill 1899 , which is defined based on the presence of secondary plates in addition to weakly fasciolar, tabulate plates; all of which are absent. The weakly stellate to stellate body shape ( R /r=1.93) and its depth, 572 to 1593 m are also consistent with Pillsburiaster species.

Figures

FIGURE 9. Pillsburiaster micropeltus nov. comb. Holotype USNM 21164. A. Abactinal. B. Closeup of coarse abactinal granules. C. Armtip. D. Actinal. E. Adambulacral plates, furrow and subambulacral spination. Scale bar=5.0 mm: A, D; Scale bar=2.0 mm: B; Scale bar=3.0 mm: C; Scale bar=2.0 mm: E.