Cetacea of any animal on earth, averaging and in mature males. The brain to body mass ratio in some odontocetes, such as belugas and narwhals, is second only to humans. In some whales, however, it is less than half that of humans: 0.9% versus 2.1%. The sperm whale ("Physeter macrocephalus") is the largest of all toothed predatory animals and possesses the largest brain. The cetacean skeleton is largely made up of cortical bone, which stabilizes the animal in the water. For this reason, the usual terrestrial compact bones, which are finely woven cancellous bone, are replaced with lighter and more elastic
Cryptid whale female individual on Orkney, saying its dorsal fins was similar to a "mizzen mast", and the whale, based on Sibbald’s account, was described as "P. tursio". However, naturalist Georges Cuvier disregarded Sibbald’s claim as a bad description of the carcass, as well as dismissing the name "P. tursio". Another alleged sighting was off the Annapolis Basin, Nova Scotia, Canada on September 27, 1946, where the creature was apparently trapped there for 2 days. Its length was estimated to be between . The Alula whale, or the Alula Killer, or "Orcinus mörzer-bruynsus", was discussed and illustrated for the first time, but