Macroraptorial sperm whale

Macroraptorial sperm whales were highly predatory whales of the sperm whale superfamily (Physeteroidea) of the Miocene epoch that hunted large marine mammals, including other whales, using their large teeth. They consist of five genera: Acrophyseter, Albicetus, Brygmophyseter, Livyatan, and Zygophyseter. All species are known by at least a skull, and are informally grouped without a family designation. They were all likely the apex predator of their habitats, comparable to the modern day killer whale (Orcinus orca), and achieved great lengths, with one species–Livyatan–measuring about 13.5–17.5 m (44–57 ft).