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.
Physeteroidea is a superfamily that includes three extant species of whales: the sperm whale, in the genus Physeter, and the pygmy sperm whale and dwarf sperm whale, in the genus Kogia. In the past, these genera have sometimes been united in a single family, the Physeteridae, with the two Kogia species in the subfamily Kogiinae; however, recent practice is to allocate the genus Kogia to its own family, the Kogiidae, leaving the Physeteridae as a monotypic family, although additional fossil representatives of both families are known.
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'.
Zygophyseter varolai is an extinct sperm whale that lived during the Tortonian age of the Late Miocene 11.2 to 7.6 million years ago. It is known from a single specimen from the Pietra Leccese Formation in Italy. It was a member of a stem group of fossil macroraptorial sperm whales also including Brygmophyseter, Acrophyseter, and Livyatan. It probably grew to be around 6.5 to 7 meters in length and shared some characteristics with other raptorials, such as large teeth with tooth enamel that were functional in both the upper and lower jaws which the modern sperm whale lacks. It also had a beak, the ability to echolocate prey, and could have probably swum faster than the modern-day sperm whale which can reach 4 kilometers per hour (2.5 mph). These were probably used in the capture of large prey, such as large fish, seals, and whales. In fact, its common name, the killer sperm whale, refers to its feeding habits that would have had a resemblance to the modern-day killer whale.
Brygmophyseter, known as the biting sperm whale, is an extinct genus of toothed whale in the sperm whale family with one species, B. shigensis. When it was first described in 1994, the species was placed in the genus Scaldicetus based on tooth morphology, but this was later revised in 1995. In 2006, it was classified into the genus Naganocetus, which is considered to be a junior synonym. The only known specimen, a nearly complete skeleton, was dated to be around 16–15 million years old. Brygmophyseter is thought to have been 6.5–7 meters (21–23 ft) long, and it probably had 11 or 12 teeth in the upper and lower jaws. Brygmophyseter is part of a group of macroraptorial sperm whales which tended to be apex predators using their large teeth to catch struggling prey such as whales. It had a spermaceti organ which was probably used for biosonar like in the modern sperm whale. The whale has made an appearance on The History Channel's TV series Jurassic Fight Club.
Choneziphius is an extinct genus of ziphiidae cetaceans, with two species known from the Miocene: C. planirostris and C. leidyi. Known from the shore of Belgium, Portugal and Spain.
Globicetus is an extinct genus of ziphiidae cetaceans, with one species, G. hiberus, from the Miocene of Portugal and Spain. The holotype is a skull in the Museu da Lourinhã, in Portugal. G. hiberus is notable for having a large, spherical mass of bone on its rostrum.
Imocetus is an extinct genus of ziphiid cetaceans, with one species, G. piscatus, from the Miocene of Portugal and Spain. The etymology is after imum that means "ocean floor", and cetus that means "whale". Piscatus means "fished". The type specimen is at Museu da Lourinhã.
The Pisco Formation is a geologic formation located in Peru, on the southern coastal desert of Ica and Arequipa. The approximately 640 metres (2,100 ft) thick formation was deposited in the Pisco Basin, spanning an age from the Late Miocene up to the Early Pliocene, roughly from 9.6 to 4.5 Ma. The tuffaceous sandstones, diatomaceous siltstones, conglomerates and dolomites were deposited in a lagoonal to near-shore environment, in bays similar to other Pacific South American formations as the Bahía Inglesa and Coquimbo Formations of Chile.
Lophocetus is an extinct genus of dolphin belonging to the clade Delphinida that is known from late Miocene (Tortonian) marine deposits in California and Maryland. Although usually placed in Kentriodontidae, recent studies have found it only distantly related to Kentriodon.
Squaloziphius is an extinct genus of odontocete cetacean from the Early Miocene (Aquitanian)-aged Clallam Formation of Washington state.
Beneziphius is an extinct genus of ziphiid cetacean known from late Miocene to Pliocene marine deposits in Belgium and fishing grounds off Spain. The genus name honors Pierre-Joseph van Beneden, who pioneered the study of Neogene marine mammals from Belgium.
Khoikhoicetus is an extinct genus of ziphiid cetacean known from skulls found on seafloor sediments of probable Miocene age off the coast of South Africa and the Kerguelen Islands.
Africanacetus is an extinct genus of ziphiid cetacean known from skulls found in seafloor sediments of Late Miocene to Early Pliocene age off the coasts of South Africa and Brazil.
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, and achieved great lengths, with one species—Livyatan—measuring about 13.5–17.5 m (44–57 ft).
Pisco Basin is a sedimentary basin extending over 300 kilometres (190 mi) in southwestern Peru. The basin has a 2 kilometres (6,600 ft) thick sedimentary fill, which is about half the thickness of more northern foreland basins in Peru.
Chavinziphius is an extinct genus of ziphiid cetacean known from Messinian age marine deposits in the Pisco Formation in Peru. There is only one known species, Chavinziphius maxillocristatus.
Messapicetus is an extinct genus of beaked whale from the Late Miocene. It currently holds two species, M. longirostris from the Tortonian of Italy and M. gregarius from the Pisco Formation of Peru. However, a third unnamed species is represented in the St. Marys Formation of Maryland known from fragmentary material. M. gregarius is sexually dimorphic, males having tusks which are hypothesized to have been used in intraspecific combat for mates as in extant (living) beaked whales.
Xhosacetus is a genus of ziphiid cetaceans with a single species, Xhosacetus hendeysi. It was classified from fossils found off the coast of the Kerguelen islands in 1,145 meter deep water.
