• killer whale
• orca
• Orcinus
• Orcinus citoniensis
• palaeoecology
• phylogeny

The anatomical redescription and the phylogenetic analyses confirm the original assignation of the specimen to the genus Orcinus and its referral to an extinct species that is clearly distinct from the extant Orcinus orca. The morphological cladistic analysis supports the validity of the clade Orcininae consisting of Eodelphinus, Hemisyntrachelus, Orcinus, and Pseudorca. Orcinus citoniensis relied on proportionally smaller preys than O. orca and P. crassidens and its diet was mostly composed of relatively small- to medium-sized fishes. There are no evidence supporting a frequent inclusion of marine mammals or particularly big bony fishes in the diet of O. citoniensis. Nonetheless, thanks to the large size and robustness of its teeth, O. citoniensis could have occasionally exhibited macroraptorial biting and tearing.