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.
Modeling predicts blue whales' foraging behavior,...
on July 18, 2019 at 3:03 am
Scientists can predict where and when blue whales are most likely to be foraging for food in the California Current Ecosystem, providing new insight that could aid in the management of the endangered population in light of climate change and blue whale mortality due to ship strikes. […]
New research helps predict locations of blue...
on July 10, 2019 at 5:40 pm
A new model based on daily oceanographic data and the movements of tagged whales has opened the potential for stakeholders to see where in the ocean endangered blue whales are most likely to be so that ships can avoid hitting them. […]
Narwhals and belugas can interbreed
on June 20, 2019 at 2:00 pm
A team of researchers has compiled the first and only evidence that narwhals and beluga whales can breed successfully. DNA and stable isotope analysis of an anomalous skull from the Natural History Museum of Denmark has allowed researchers to confirm the existence of a narwhal-beluga hybrid. […]
Dolphins form friendships through shared...
on June 12, 2019 at 1:39 pm
When it comes to making friends, it appears dolphins are just like us and form close friendships with other dolphins that have a common interest. The research provides further insight into the social habits of these remarkable animals. […]
New sub-species of pilot whale identified in...
on June 3, 2019 at 2:26 pm
Short-finned pilot whales are found over a wide swath of the world's oceans, with habitats in the Indian, and Pacific, and North Atlantic oceans. Despite this wide distribution, the whales have been recognized as a single species -- but a recent study has found that two unique subspecies actually exist. […]
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Theory that ridged skin helps dolphins debunked
on July 19, 2019 at 12:00 pm
A dolphin is obviously not a golf ball. However, many scientists believed that the way one slips through the water and the other through the air owed to the same cause: similarities in surface texture and their effect on drag and locomotion. […]
Georgia beachgoers help pilot whales from...
on July 17, 2019 at 5:46 pm
A summer afternoon at the beach quickly became a scramble to save a pod of disoriented pilot whales, with vacationers joining lifeguards and state wildlife crews in the water trying to keep roughly 30 of the large marine mammals from beaching themselves on the Georgia coast. […]
Hurricane Barry's rain and floods hammer Gulf...
on July 14, 2019 at 2:17 pm
Hurricane Barry could affect the environment of the Gulf coast and Lower Mississippi Valley in numerous ways, from accelerating runoff of farmland nutrients to toppling trees and damaging wildlife habitat and fisheries, scientists say. […]
Tropical storm, river flooding hammer Gulf...
on July 13, 2019 at 9:07 am
Tropical Storm Barry could affect the environment of the Gulf coast and Lower Mississippi Valley in numerous ways, from accelerating runoff of farmland nutrients to toppling trees and damaging wildlife habitat and fisheries, scientists say. […]
DDT contaminants in marine mammals may threaten...
on July 12, 2019 at 2:40 pm
The California condor's dramatic recovery from near-extinction was aided by removal of toxic substances from the land, which accumulated in animals whose carrion they ate. […]