Please answer the following question: Information: - The toothed whales (systematic name Odontoceti) are a parvorder of cetaceans that includes all the dolphins and porpoises, as well as the whales that have teeth, such as the beaked whales and sperm whales. Seventy-three species of toothed whales (also called odontocetes) are described. They are one of two living groups of cetaceans, the other being the baleen whales (Mysticeti), which have baleen instead of teeth. The two groups are thought to have diverged around 34 million years ago (mya). - Baleen whales (systematic name Mysticeti), known earlier as whalebone whales, form a parvorder of the infraorder Cetacea (whales, dolphins and porpoises). They are a widely distributed and diverse parvorder of carnivorous marine mammals. Mysticeti comprise the families Balaenidae (right whales), Balaenopteridae (rorquals), Cetotheriidae (the pygmy right whale), and Eschrichtiidae (the gray whale). There are currently 15 species of baleen whale. While cetaceans were historically thought to have descended from mesonychids, molecular evidence supports them as relatives of even-toed ungulates (Artiodactyla). Baleen whales split from toothed whales (Odontoceti) around 34 million years ago. - Balaenidae is a family of whales of the parvorder Mysticeti that contains two living genera. Historically, it is known as the right whale family, as it was thought to contain only species of right whales. Through most of the 20th Century, however, that became a much-debated (and unresolved) topic amongst the scientific community. Finally, in the early 2000s, science reached a definitive conclusion: the bowhead whale, once commonly known as the Greenland right whale, was not in fact a right whale. The family of Balaenids, therefore, comprises the right whales (genus "Eubalaena"), and in a genus all to its own, the very closely related bowhead whale (genus "Balaena"). - Porpoises are a group of fully aquatic marine mammals that are sometimes referred to as mereswine, all of which are classified under the family Phocoenidae, parvorder Odontoceti (toothed whales). There are six extant species of porpoise. They are small toothed whales that are very closely related to oceanic dolphins. The most obvious visible difference between the two groups is that porpoises have shorter beaks and flattened, spade-shaped teeth distinct from the conical teeth of dolphins. Porpoises, and other cetaceans, belong to the clade Cetartiodactyla with even-toed ungulates, and their closest living relatives are the hippopotamuses, having diverged from them about 40 million years ago. - Iniidae is a family of river dolphins containing one living and four extinct genera. - The common hippopotamus ("Hippopotamus amphibius"), or hippo, is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae, the other being the pygmy hippopotamus ("Choeropsis liberiensis" or "Hexaprotodon liberiensis"). The name comes from the ancient Greek for "river horse". After the elephant and rhinoceros, the common hippopotamus is the third-largest type of land mammal and the heaviest extant artiodactyl. Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, the closest living relatives of the Hippopotamidae are cetaceans (whales, porpoises, etc.) from which they diverged about . The common ancestor of whales and hippos split from other even-toed ungulates around . The earliest known hippopotamus fossils, belonging to the genus "Kenyapotamus" in Africa, date to around . - Beaked whales are the members of the family Ziphiidae, which consists of 22 species. These toothed whales are notable for their elongated beaks. Among air-breathing animals, beaked whales are some of the most extreme divers: Cuvier's beaked whales regularly dive for an hour at a depth over , and the longest and deepest foraging dive recorded is 137.5 minutes at . This is the greatest dive-depth known for a mammal. - Latin (Latin: ) is a classical language belonging to the Italic branch of the Indo-European languages. The Latin alphabet is derived from the Etruscan and Greek alphabets. - Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as seals, whales, manatees, sea otters and polar bears. They do not represent a distinct taxon or systematic grouping, but rather have a paraphyletic relation. They are also unified by their reliance on the marine environment for feeding. - Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. They are an informal grouping within the infraorder Cetacea, usually excluding dolphins and porpoises. Whales, dolphins and porpoises belong to the order Cetartiodactyla with even-toed ungulates and their closest living relatives are the hippopotamuses, having diverged about 40 million years ago. The two parvorders of whales, baleen whales (Mysticeti) and toothed whales (Odontoceti), are thought to have split apart around 34 million years ago. The whales comprise eight extant families: Balaenopteridae (the rorquals), Balaenidae (right whales), Cetotheriidae (the pygmy right whale), Eschrichtiidae (the gray whale), Monodontidae (belugas and narwhals), Physeteridae (the sperm whale), Kogiidae (the dwarf and pygmy sperm whale), and Ziphiidae (the beaked whales). - Rorquals (Balaenopteridae) are the largest group of baleen whales, a family with nine extant species in two genera. They include what is believed to be the largest animal that has ever lived, the blue whale, which can reach , and the fin whale, which reaches ; even the smallest of the group, the northern minke whale, reaches . - The Kogiidae are a family comprising two extant species of Cetacea. A number of genera are extinct. - The narwhal, or narwhale ("Monodon monoceros"), is a medium-sized toothed whale that possesses a large "tusk" from a protruding canine tooth. It lives year-round in the Arctic waters around Greenland, Canada, and Russia. It is one of two living species of whale in the Monodontidae family, along with the beluga whale. The narwhal males are distinguished by a long, straight, helical tusk, which is an elongated upper left canine. The narwhal was one of many species described by Carl Linnaeus in his publication "Systema Naturae" in 1758. - Dolphins are a widely distributed and diverse group of fully aquatic marine mammals . They are an informal grouping within the order Cetacea , excluding whales and porpoises , so to zoologists the grouping is paraphyletic . The dolphins comprise the extant families Delphinidae ( the oceanic dolphins ) , Platanistidae ( the Indian river dolphins ) , Iniidae ( the new world river dolphins ) , and Pontoporiidae ( the brackish dolphins ) . There are 40 extant species of dolphins . Dolphins , alongside other cetaceans , belong to the clade Cetartiodactyla with even - toed ungulates , and their closest living relatives are the hippopotamuses , having diverged about 40 million years ago . Dolphins range in size from the 1.7 metres ( 5.6 ft ) long and 50 kilograms ( 110 lb ) Maui 's dolphin to the 9.5 metres ( 31 ft ) and 10 metric tons ( 11 short tons ) killer whale . Several species exhibit sexual dimorphism , in that the males are larger than females . They have streamlined bodies and two limbs that are modified into flippers . Though not quite as flexible as seals , some dolphins can travel at 55.5 kilometres per hour ( 34.5 mph ) . Dolphins use their conical shaped teeth to capture fast moving prey . They have well - developed hearing their hearing , which is adapted for both air and water , is so well developed that some can survive even if they are blind . Some species are well adapted for diving to great depths . They have a layer of fat , or blubber , under the skin to keep warm in the cold water . Although dolphins are widespread , most species prefer the warmer waters of the tropic zones , but some , like the right whale dolphin , prefer colder climates . Dolphins feed largely on fish and squid , but a few , like the killer whale , feed on large mammals , like seals . Male dolphins typically mate with multiple females every year , but females only mate every two to three years . Calves are typically born in the spring and summer months and females bear all the responsibility for raising them . Mothers of... - Baleen is a filter-feeder system inside the mouths of baleen whales. The baleen system works by whale opening its mouth underwater and taking in water. The whale then pushes the water out, and animals such as krill are filtered by the baleen and remain as food source for the whale. Baleen is similar to bristles and is made of keratin, the same substance found in human fingernails and hair. Baleen is a skin derivative. Some whales, such as the bowhead whale, have longer baleen than others. Other whales, such as the gray whale, only use one side of their baleen. These baleen bristles are arranged in plates across the upper jaw of the whale. Baleen is often called whalebone, but that name also can refer to the normal bones of whales, which have often been used as a material, especially as a cheaper substitute for ivory in carving. - Aquatic and semiaquatic mammals are a diverse group of mammals that dwell partly or entirely in bodies of water. They include the various marine mammals who dwell in oceans, as well as various freshwater species, such as the European otter. They are not a taxon and are not unified by any distinct biological grouping, but rather their dependence on and integral relation to aquatic ecosystems. The level of dependence on aquatic life are vastly different among species, with the Amazonian manatee and river dolphins being completely aquatic and fully dependent on aquatic ecosystems; whereas the Baikal seal feeds underwater but rests, molts, and breeds on land; and the capybara and hippopotamus are able to venture in and out of water in search of food. - Eschrichtiidae or the gray whales is a family of baleen whale (suborder Mysticeti) with a single extant species, the gray whale ("Eschrichtius robustus"). The family, however, also includes three described fossil genera: "Archaeschrichtius" and "Eschrichtioides" from the Miocene and Pliocene of Italy respectively, and "Gricetoides" from the Pliocene of North Carolina. The names of the extant genus and the family honours Danish zoologist Daniel Eschricht. - The gray whale ("Eschrichtius robustus"), also known as the grey whale, gray back whale, Pacific gray whale, or California gray whale is a baleen whale that migrates between feeding and breeding grounds yearly. It reaches a length of , a weight of , and lives between 55 and 70 years. The common name of the whale comes from the gray patches and white mottling on its dark skin. Gray whales were once called devil fish because of their fighting behavior when hunted. The gray whale is the sole living species in the genus Eschrichtius, which in turn is the sole living genus in the family Eschrichtiidae. This mammal descended from filter-feeding whales that appeared at the beginning of the Oligocene, over 30 million years ago. - The cetacean family Monodontidae comprises two unusual whale species, the narwhal, in which the male has a long tusk, and the dorsal fin-lacking, pure white beluga whale. They are native to coastal regions and pack ice around the Arctic Sea. Belugas can be found in the far north of the Atlantic and Pacific Oceans; the distribution of narwhals is restricted to the Arctic and Atlantic Oceans. - The even-toed ungulates (order Artiodactyla) are ungulates (hoofed animals) whose weight is borne equally by the third and fourth toes. By contrast, odd-toed ungulates, such as horses, bear their weight primarily on their third toe. The aquatic Cetaceans (whales, dolphins, and porpoises) evolved from even-toed ungulate ancestors, and therefore modern taxonomic classification combines Artiodactyla and Cetacea into Cetartiodactyla. - River dolphins are a widely distributed group of fully aquatic mammals that reside exclusively in freshwater or brackish water. They are an informal grouping of dolphins, which is a paraphyletic group within the infraorder Cetacea. The river dolphins comprise the extant families Platanistidae (the Indian dolphins), Iniidae (the Amazonian dolphins), and Pontoporiidae (the brackish dolphins). There are five extant species of river dolphins, and two subspecies. River dolphins, alongside other cetaceans, belong to the clade Cetartiodactyla, with even-toed ungulates, and their closest living relatives the hippopotamuses, having diverged about 40 million years ago. - A clade (from , "klados", "branch") is a group of organisms that consists of a common ancestor and all its lineal descendants, and represents a single "branch" on the "tree of life". - The sperm whale ("Physeter macrocephalus"), or cachalot, is the largest of the toothed whales and the largest toothed predator. It is the only living member of genus Physeter, and one of three extant species in the sperm whale family, along with the pygmy sperm whale and dwarf sperm whale of the genus "Kogia". - Cetacea are a widely distributed and diverse clade of aquatic mammals that today consists of the whales, dolphins, and porpoises. Cetaceans are carnivorous and finned. Most species live in the sea, some in rivers. The name is derived from the Latin "cetus" "whale" and Greek "ketos" "huge fish". What is the relationship between 'dolphin' and 'common name'?
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