Dolphins, along with whales and porpoises, are thought to be descendants of terrestrial mammals, most likely of the Artiodactyl order.

Modern dolphin skeletons have two small rod shaped pelvic bones thought to be vestigial hind legs.

In October of 2006 an unusual Bottlenose Dolphin was captured in Japan that had small fins on either side of the genital slit, which scientists believe to be a more pronounced development of these vestigal hind legs.

Dolphins are often regarded as one of Earth's most intelligent species, though it is hard to say just how intelligent dolphins are as straightforward comparisons of species' relative intelligence are complicated by differences in sensory apparatus, response modes, and nature of cognition..

For more information about the topic Dolphin, read the full article at Wikipedia.org, or see the following related articles:

Porpoise — The porpoises are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. They are distinct from dolphins, although the ...  > read more

Toothed whale — The toothed whales (systematic name Odontoceti) form a suborder of the cetaceans. As the name suggests, the suborder is characterized by having ...  > read more

Gray Whale — The Gray Whale or Grey Whale, more recently called the Eastern Pacific Gray Whale, is a whale that travels between feeding and breeding grounds ...  > read more

Baleen whale — The baleen whales, also called whalebone whales or great whales, form a suborder of the order cetacea. The distinguishing feature between this ...  > read more

Related Stories

Rare Sighting Of Threatened Bottlenose Dolphins In English Channel (May 14, 2007) — On a crossing of the English Channel on the 5th of May, a large group of approximately 30 Bottlenose Dolphin was sighted. The dolphins, which are threatened in UK waters, were recorded 4 miles off of ...  > read more

Dolphins Get A Lift From Delta Wing Technology (June 28, 2009) — Dolphins are supremely agile swimmers, but it wasn't clear how their fins help them maneuver though water. Building scale models of whale and dolphins' fins, a team of US scientists has found that ...  > read more

Where Have All The Dolphins Gone This Summer? (August 22, 2007) — Researchers from the wildlife conservation charity Marinelife are extremely concerned about what it is NOT seeing this summer in the Bay of Biscay. The BDRP surveys have detected more than 20 species ...  > read more

Net Gain For Endangered Dolphins (July 16, 2008) — The rarest marine dolphin in the world -- down to 111 individuals following decades of entanglement in fishing nets -- is now to receive protection over more of its range from the New Zealand ...  > read more

Scientists Discover Secret Of Dolphin Speed: How Dolphins Evolved To Fly Like Birds Under Water (May 17, 2004) — Physicists in Japan have discovered how the surface of a dolphin's skin reduces drag and helps them glide smoothly and quickly through water. These findings could help scientists design faster, ...  > read more

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