Beaked whales are a family of cetaceans noted as being one of the least-known groups of mammals because of their deep-sea habitat, reclusive behavior and apparent low abundance. Only three or four of the 24 existing species are reasonably well-known. Baird's beaked whales and Cuvier's beaked whales were subject to commercial exploitation, off the coast of Japan, while the northern bottlenose whale was extensively hunted in the northern part of the North Atlantic in the late 19th and early 20th centuries.
Mesoplodont whales are 16 species of toothed whale in the genus Mesoplodon, making it the largest genus in the cetacean order. Two species were described as recently as 1991 and 2002, and marine biologists predict the discovery of more species in the future. A new species was described in 2021. They are the most poorly known group of large mammals. The generic name "mesoplodon" comes from the Greek meso- (middle) - hopla (arms) - odon (teeth), and may be translated as 'armed with a tooth in the centre of the jaw'.
The ginkgo-toothed beaked whale is a poorly known species of whale even for a beaked whale, and was named for the unusual shape of its dual teeth. It is a fairly typical-looking species, but is notable for the males not having any scarring.
Gray's beaked whale, sometimes known as Haast's beaked whale, the scamperdown whale, or the southern beaked whale, is one of the better-known members of the genus Mesoplodon. This species is fairly gregarious and strands relatively frequently for a beaked whale. In the Māori language, this species is called hakurā or iheihe.
Hector's beaked whale, is a small mesoplodont living in the Southern Hemisphere. This whale is named after Sir James Hector, a founder of the colonial museum in Wellington, New Zealand. The species has rarely been seen in the wild.
The strap-toothed beaked whale, also known as Layard's beaked whale, is one of the largest members of the Mesoplodon genus, growing to 6.2 m (20 ft) in length and reaching up to 1,300 kg (2,900 lb). The common and scientific name was given in honor of Edgar Leopold Layard, the curator of the South African Museum, who prepared drawings of a skull and sent them to the British taxonomist John Edward Gray, who described the species in 1865.
The tropical bottlenose whale, also known as the Indo-Pacific beaked whale or Longman's beaked whale, was considered to be the world's rarest cetacean until recently, but the spade-toothed whale now holds that position. As of 2010, the species is now known from nearly a dozen strandings and over 65 sightings. This is the only species in the genus Indopacetus.
Stejneger's beaked whale, also known as the Bering Sea beaked whale or the saber-toothed whale, is a relatively unknown member of the genus Mesoplodon inhabiting the North Pacific Ocean. Leonhard Hess Stejneger collected the type specimen on Bering Island in 1883, from which Frederick W. True provided the species' description in 1885. In 1904, the first complete skull was collected, which confirmed the species' validity. The most noteworthy characteristic of the males is the very large, saber-like teeth, hence the name.
The four-toothed whales or giant beaked whales are beaked whales in the genus Berardius. They include Arnoux's beaked whale in cold Southern Hemispheric waters, and Baird's beaked whale in the cold temperate waters of the North Pacific. A third species, Sato's beaked whale, was distinguished from B. bairdii in the 2010s.
Arnoux's beaked whale, also called the southern four-toothed whale, southern beaked whale, New Zealand beaked whale, southern giant bottlenose whale and southern porpoise whale is one of the species of Berardius. Arnoux's and Baird's beaked whales are so similar that researchers debated whether or not they are simply two populations of the same species, until genetic evidence and their wide geographical separation led them to be classified as separate. Little is known about their behavior due to infrequent encounters with live individuals.
Baird's beaked whale, also known as the northern giant bottlenose whale, North Pacific bottlenose whale, giant four-toothed whale, northern four-toothed whale and the North Pacific four-toothed whale, is a species of whale from the genus Berardius. Baird's and Arnoux's beaked whales are so similar that researchers have debated whether or not they are simply two populations of the same species. However, genetic evidence and their wide geographical separation has led them to be classified as separate. Baird's beaked whale is the second largest living species of toothed whale after the sperm whale.
Perrin's beaked whale is part of the toothed whale suborder and is one of over 90 known cetaceans in existence today. Beaked whales are part of the family Ziphiidae, which are the second most diverse group out of all marine mammals with over 20 species currently recognized. Although diverse, little is understood about these timid, deep divers that can dive for up to two hours. The whales are partially named after their beak shaped jaw, which extends from their small head. The genus name Mesoplodon comes from the Greek meanings of meso- (middle), - hopla (arms), - odon (teeth), and may be translated as 'armed with a tooth in the center of the jaw'.
The spade-toothed whale is the rarest species of beaked whale. Most specimens found have been in the South Pacific, mostly in New Zealand, but they have also been found in Chile. It is a species of which there is very little known.
The southern bottlenose whale is a species of whale, in the ziphiid family, one of two members of the genus Hyperoodon. Seldom observed, the southern bottlenose whale is resident in Antarctic waters. The species was first described by English zoologist William Henry Flower in 1882, based on a water-worn skull from Lewis Island, in the Dampier Archipelago, Western Australia. They live in deep ocean waters over 1000 meters.
Deraniyagala's beaked whale is a species of mesoplodont whale closely related to the ginkgo-toothed beaked whale.
Cryptid whales are cetaceans claimed to exist by cryptozoologists on the basis of informal sightings, but not accepted by taxonomists as they lack formal descriptions of type specimens. Over the past few hundred years, sailors and whalers have reported seeing whales they cannot identify. The most well-known are Giglioli's Whale, the rhinoceros dolphin, Trunko, the high-finned sperm whale, and the Alula whale.
