鲸须
最早能够证明鲸须的存在的化石距今也只有1500万年，但是鲸须其实很少留下化石，所以有科学家认为鲸须的存在比这时间早的多。不过，早期的须鲸也是拥有牙齿的。
未确认鲸鱼
The high-finned sperm whale, or the high-finned cachalot, is an alleged variant or relative of the known sperm whale, "Physeter macrocephalus", with an unusually tall dorsal fin from the North Atlantic. The physician Sir Robert Sibbald, in 1687, described an alleged stranded 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 two days. Its length was estimated to be between .