Astralium rotularium, common name the rotary star shell or the knob star shell, is a species of sea snail, a marine gastropod mollusk in the family Turbinidae, the turban snails.Alf A. & Kreipl K. (2011) The family Turbinidae. Subfamilies Turbininae Rafinesque, 1815 and Prisogasterinae Hickman & McLean, 1990. In: G.T. Poppe & K. Groh (eds), A Conchological Iconography. Hackenheim: Conchbooks. pp. 1-82, pls 104-245.
Description The size of the shell varies between 25 mm and 50 mm. The white, subdepressed, imperforate shell has a conoid shape. The spire is subacute. The six whorls are obliquely finely costulate with numerous prominent imbricating laterally compressed plicae at the sutures. The body whorl is carinated with plicate-nodose carina. The base of the shell is convex, squamosely concentrically lirate. The white columella is arcuate, not dentate. The aperture is oblique.G.W. Tryon (1888), Manual of Conchology X; Academy of Natural Sciences, Philadelphia
Distribution This marine species is endemic to Australia and occurs off the Northern Territory, Queensland and Western Australia.
References
Wilson, B.R. & Gillett, K. 1971. Australian Shells: illustrating and describing 600 species of marine gastropods found in Australian waters. Sydney : Reed Books 168 pp Coleman, N. 1975. What Shell is That? Sydney : Lansdowne Press 298 pp. Wilson, B. 1993. Australian Marine Shells. Prosobranch Gastropods. Kallaroo, Western Australia : Odyssey Publishing Vol. 1 408 pp.