Tree of Life
Plant Flower, Tree
Invertebrate Octopus, Ant, Bee, Butterfly, Spider, Lobster
Vertebrate Fish, Seahorse, Ray, Shark, Frog, Turtle, Tortoise, Dinosaur
Bird, Ostrich, Owl, Crow, Parrot
Mammal Bat, Rabbit, Giraffe, Camel, Horse, Elephant, Mammoth
Whale, Dolphin, Walrus, Seal, Polar Bear, Bear, Cat, Tiger, Lion, Dog, Wolf
Monkey, Chimpanzee, Human
These are organized by a classification scheme developed exclusively for Cosma. More…
dolphin : any of various small marine toothed whales (family Delphinidae) with the snout more or less elongated into a beak and the neck vertebrae partially fused
Note: While not closely related, dolphins and porpoises share a physical resemblance that often leads to misidentification. Dolphins typically have cone-shaped teeth, curved dorsal fins, and elongated beaks with large mouths, while porpoises have flat, spade-shaped teeth, triangular dorsal fins, and shortened beaks with smaller mouths. — Webster
Dolphins are a widely distributed and diverse group of aquatic 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), and the extinct Lipotidae (baiji or Chinese river dolphin). There are 40 extant species of dolphins. Dolphins, alongside other cetaceans, belong to the clade Cetartiodactyla with even-toed ungulates. Their closest living relatives are the hippopotamuses, having diverged about 40 million years ago.
Dolphins range in size from the 1.7 m (5.6 ft) long and 50 kg (110 lb) Maui’s dolphin to the 9.5 m (31 ft) and 10 t (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 km/h (34.5 mph). Dolphins use their conical shaped teeth to capture fast moving prey. They have well-developed hearing which is adapted for both air and water and 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 some species fast and nurse their young for a relatively long period of time. Dolphins produce a variety of vocalizations, usually in the form of clicks and whistles. — Wikipedia
Dolphins and Whales News -- ScienceDaily Whales and dolphins. Whale songs, beaching, endangered status -- current research news on all cetaceans.
Blue whales switch to daytime singing before...
on October 1, 2020 at 3:36 pm
Through the use of two advanced audio recording technologies, researchers have found that blue whales switch from nighttime to daytime singing when they are starting to migrate.
Call of the wild: Individual dolphin calls used...
on August 27, 2020 at 2:21 pm
A new study has shown for the first time that acoustic monitoring can be used in place of photographs to generate abundance estimates of dolphin populations.
Ichthyosaur's last meal is evidence of Triassic...
on August 20, 2020 at 3:28 pm
Some 240 million years ago, a dolphin-like ichthyosaur ripped to pieces and swallowed another marine reptile only a little smaller than itself. Then it almost immediately died and was fossilized, preserving the first evidence of megapredation, or a large animal preying on another large animal.
Study finds high levels of toxic pollutants in...
on August 6, 2020 at 7:36 pm
Researchers examined toxins in tissue concentrations and pathology data from 83 stranded dolphins and whales from 2012 to 2018. They looked at 11 different animal species to test for 17 different substances. The study is the first to report on concentrations in blubber tissues of stranded cetaceans of atrazine, DEP, NPE and triclosan. It also is the first to report concentrations of toxicants in a white-beaked dolphin and in Gervais' beaked whales.
Dolphin calf entangled in fishing line only lived...
on August 4, 2020 at 1:33 pm
Researchers examined the outcome of an entangled bottlenose dolphin calf with monofilament fishing line wrapped tightly around its upper jaw. It was successfully disentangled and immediately released it back into its natural habitat. Surviving only two years, results showed long-term severe damage due to this entanglement including emaciation. There are about 1,000 bottlenose dolphins that live in the Indian River Lagoon, which also is a very popular location for recreational fishing.
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6 dolphins found dead in 'historic' stranding in...
on September 30, 2020 at 7:04 pm
Six dolphins were found dead in an Alabama marsh last week in what experts call an "historic mass stranding."
NASA nets Dolphin as an extratropical storm
on September 24, 2020 at 8:03 pm
NASA's Aqua satellite caught a visible image of Dolphin after it passed east central Japan on Sept. 24, where it became an extratropical storm in the Northwestern Pacific Ocean.
NASA finds Dolphin swimming against wind shear
on September 23, 2020 at 4:01 pm
NASA's Terra satellite provided a visible image of a slightly elongated Tropical Storm Dolphin as it battled wind shear upon its approach to east central Japan.
NASA catches Tropical Storm Dolphin swimming north
on September 22, 2020 at 4:57 pm
NASA's Terra satellite obtained visible imagery of Tropical Storm Dolphin as it continued moving north though the Northwestern Pacific Ocean on a track toward east central Japan.
Open-ocean fish farm proposed off San Diego coast...
on September 21, 2020 at 8:20 pm
A prestigious San Diego research institute and a Long Beach social benefit investment group are teaming to create what could be the first fish farm in federal waters.