We demonstrate the relation between supercooling of n-alkane melts and the appearance or nonappearance of rotator phases. Supercooling occurs for the shorter, even chain lengths. The lack of supercooling in most n-alkane melts is discussed in terms of surface crystallization. We argue that melt crystallization of the nonrotator triclinic crystal phase is likely mediated by surface-crystallization-induced nucleation of a metastable rotator phase.