Bottlenose dolphins are toothed whales in the genus Tursiops. They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus contains three species: the common bottlenose dolphin, the Indo-Pacific bottlenose dolphin, and Tamanend's bottlenose dolphin. Others, like the Burrunan dolphin, may be alternately considered their own species or be subspecies of T. aduncus. Bottlenose dolphins inhabit warm and temperate seas worldwide, being found everywhere except for the Arctic and Antarctic Circle regions. Their name derives from the Latin tursio (dolphin) and truncatus for the truncated teeth.
Bottlenose dolphin
Indo-Pacific bottlenose dolphin, T. aduncus
Wolphin Kawili'Kai at the Sea Life Park in Hawaii
The fossil species Tursiops osennae
The toothed whales are a parvorder of cetaceans that includes dolphins, porpoises, and all other whales possessing teeth, such as the beaked whales and sperm whales. 73 species of toothed whales 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).
A whale as depicted by Conrad Gessner, 1587, in his Historiae animalium
Fossil of Squalodon
Pacific white-sided dolphins porpoising
Spectrogram of dolphin vocalizations. Whistles, whines, and clicks are visible as upside down V's, horizontal striations, and vertical lines, respectively.