Variation in the adductor muscle-scar rosette of Darwinula cicatricosa Wakefield, 1994 (Ostracoda, Crustacea), and comparison with other species of Darwinula

Abstract. Variation in the morphology of the adductor muscle-scar pattern of Darwinula cicatricosa Wakefield, 1994 is demonstrated, and is shown to affect specific segments within the essentially rosette-shaped scar. Potential subdivisions of individual segments can be identified in fossil specimens as ‘scar-sutures’. All fossil and Recent species of Darwinula studied are shown to have different patterns to their adductor muscle-scar rosette. These differences can be used as an aid in species identification, particularly of fossil species, in which the muscle-scars are the best indicator of soft part morphology.