Macrodelphinus kelloggi was an orca-sized relative of the cetacean Eurhinodelphis. It lived off the coast of what is now California during the early Miocene. Because of its size, and inch-long teeth, it is believed to have been an apex predator. Macrodelphinus is known from a fragmentary skull from southern California.
Species taxanomy provided by GBIF Secretariat (2022). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2023-06-13; License: CC BY 4.0