Genus Rhipidipathes Milne-Edwards & Haime, 1857

Diagnosis. Corallum flabellate; anastomosing among some branches; polypar spines acute or blunt, smooth or tuberculate; circumpolypar spines slightly larger than interpolypar spines; hypostomal spines often equal to the circumpolypar spines but may be reduced in size or absent on some portions of the corallum.

Remarks. Although Rhipidipathes is currently in the Aphanipathidae, previous (Brugler et al. 2013; Bo et al. 2018; Terrana et al. 2021) and the present study indicate that the genus is more closely related to species in the Antipathidae . The present study suggests that Rhipidipathes shares a lineage with the genus Blastopathes Horowitz, 2020 (Fig 2). Both genera have distinct morphological differences. For example, Rhipidipathes consists of thin branches that can fuse to create flabellate “fan-like” colonies (Opresko 2004) and Blastopathes consists of thick, stem-like branches that do not fuse and possess branches that sprout from clusters to create “tree-like” colonies (Horowitz et al. 2020). Due to the differences between these “sister” genera, their family-level relationships need to be verified.

Type Species: Rhipidipathes reticulata (Esper 1795)

Type Locality: East Indian Ocean