Caninae, whose members are known as canines (/keɪnaɪnz/),[6]: 182  is the only living subfamily within Canidae, alongside the extinct Borophaginae and Hesperocyoninae.[7][1] They first appeared in North America, during the Oligocene around 35 million years ago, subsequently spreading to Asia and elsewhere in the Old World at the end of the Miocene,[6]: 122  some 7 million to 8 million years ago.[7]

The sperm whale or cachalot[a] (Physeter macrocephalus) is the largest of the toothed whales and the largest toothed predator. It is the only living member of the genus Physeter  and one of three extant species in the sperm whale superfamily Physeteroidea, along with the pygmy sperm whale and dwarf sperm whale of the genus Kogia.

The humpback whale (Megaptera novaeangliae) is a species of baleen whale. It is a rorqual (a member of the family Balaenopteridae) and is the only species in the genus Megaptera. Adults range in length from 14–17 m (46–56 ft) and weigh up to 40 metric tons (44 short tons). The humpback has a distinctive body shape, with long pectoral fins and tubercles on its head. It is known for breaching and other distinctive surface behaviors, making it popular with whale watchers. Males produce a complex song that typically lasts from 4 to 33 minutes.

The orca (Orcinus orca), or killer whale, is a toothed whale and the largest member of the oceanic dolphin family. The only extant  species in the genus Orcinus, it is recognizable by its distinct pigmentation; being mostly black on top, white on the bottom and having recognizable white eye patches. A cosmopolitan species, it inhabits a wide range of marine environments, from Arctic to Antarctic regions to tropical seas, but is more commonly documented in temperate or cooler coastal waters. Scientists have proposed dividing the global population into races, subspecies, or possibly even species.

The North Atlantic right whale (Eubalaena glacialis) is a baleen whale, one of three right whale species belonging to the genus Eubalaena,[1] all of which were formerly classified as a single species. Because of their docile nature, their slow surface-skimming feeding behaviors, their tendencies to stay close to the coast, and their high blubber content (which makes them float when they are killed, and which produces high yields of whale oil), right whales were once a preferred target for whalers. At present, they are among the most endangered whales in the world,[6] and they are protected under the U.S. Endangered Species Act and Marine Mammal Protection Act and Canada's Species at Risk Act. There are an estimated 356[7] individuals in existence in the western North Atlantic Ocean—they migrate between feeding grounds in the Labrador Sea and their winter calving areas off Georgia and Florida, an ocean area with heavy shipping traffic. In the eastern North Atlantic, on the other hand—with a total population reaching into the low teens at most—scientists believe that they may already be functionally extinct.[6][dubious – discuss] Vessel strikes and entanglement in fixed fishing gear, which together account for nearly half of all North Atlantic right whale mortality since 1970,[8] are their two greatest threats to recovery.[9][10]

The Amazon river dolphin (Inia geoffrensis), also known as the boto, bufeo or pink river dolphin, is a species of toothed whale endemic to South America and is classified in the family Iniidae. Three subspecies are currently recognized: I. g. geoffrensis (Amazon river dolphin), I. g. boliviensis (Bolivian river dolphin) and I. g. humboldtiana (Orinoco river dolphin). The position of the Araguaian river dolphin (I. araguaiaensis) within the clade is still unclear.[3][4] The three subspecies are distributed in the Amazon basin, the upper Madeira River in Bolivia, and the Orinoco basin, respectively.

The harbour porpoise (Phocoena phocoena) is one of eight extant species of porpoise. It is one of the smallest species of cetacean. As its name implies, it stays close to coastal areas or river estuaries, and as such, is the most familiar porpoise to whale watchers. This porpoise often ventures up rivers, and has been seen hundreds of kilometres from the sea. The harbour porpoise may be polytypic, with geographically distinct populations representing distinct races: P. p. phocoena in the North Atlantic and West Africa, P. p. relicta in the Black Sea and Sea of Azov, an unnamed population in the northwestern Pacific and P. p. vomerina in the northeastern Pacific.[3]

Pakicetus (meaning 'whale from Pakistan') is an extinct genus of amphibious cetacean of the family Pakicetidae, which was endemic to South Asia during the Ypresian (early Eocene) period, about 50 million years ago.[2] It was a wolf-like mammal,[3] about 1–2 m (3 ft 3 in – 6 ft 7 in) long,[4] and lived in and around water where it ate fish and other animals. The name Pakicetus comes from the fact that the first fossils of this extinct amphibious whale were discovered in Pakistan. The vast majority of paleontologists regard it as the most basal  whale, representing a transitional stage between land mammals and whales. It belongs to the even-toed ungulates with the closest living non-cetacean relative being the hippopotamus.[3]

Basilosaurus (meaning "king lizard") is a genus of large, predatory, prehistoric archaeocete whale from the late Eocene, approximately 41.3 to 33.9 million years ago (mya). First described in 1834, it was the first archaeocete and prehistoric whale known to science.[2] Fossils attributed to the type species B. cetoides were discovered in the southeastern United States. The generic name, meaning "king lizard", was given due to the initial misconception about the fossil material as that of a giant reptile. The animal was later found to be an early marine mammal, prompting attempts at renaming the creature, which failed as the rules of zoological nomenclature dictate using the original name given. The second species named in 1904, B. isis, lived in the region currently known as the Mediterranean Sea, with fossils found in North Africa and Jordan.

Equidae (commonly known as the horse family) is the taxonomic family of horses  and related animals, including asses, zebras, and many extinct species known only from fossils. The family evolved more than 50 million years ago, in the Eocene  epoch, from a small, multi-toed ungulate  into larger, single-toed animals. All extant  species are in the genus Equus, which originated in North America. Equidae belongs to the order Perissodactyla, which includes the extant tapirs and rhinoceros, and several extinct families. It is more specifically grouped within the superfamily Equoidea, the only other family being the extinct Palaeotheriidae.