Scutellastra optima is a species of true limpet, a marine gastropod mollusk in the family Patellidae.
The shell of the holotype measures .
(Original description) The shell is large, solid, and ovate in shape, with a distinctly depressed profile. Its sculpture consists of numerous low radial riblets, which are approximately equal in width to the intervals between them. These riblets are layered over a coarser underlying structure of about a dozen low, broad radial elevations.
The color is striking: the depressed spaces between the primary elevations are a dull, deep maroon, while the smaller intervals between the riblets on the raised portions exhibit a diluted shade of the same hue. The interior is white, featuring a central field clouded with cinnamon tones.
Scutellastra optima occurs in the northwestern Pacific. The holotype was obtained from Yakushima (Japan).
Nakano T. & Ozawa T. (2007). Worldwide phylogeography of limpets of the order Patellogastropoda: molecular, morphological and paleontological evidence. Journal of Molluscan Studies 73(1): 79âÂÂ99.