December 19, 2007-The ancestors of the Earth's largest mammals-whales-were tiny deerlike creatures, scientists say. A small semiaquatic fossil mammal unearthed in Kashmir in northern India represents the vital "missing link" in the evolution of whales, according to a study lead by Hans Thewissen of Northeastern Ohio Universities Colleges of Medicine and Pharmacy in Rootstown. The ancient animal-Indohyus-lived in southern Asia about 48 million years ago. The creature belongs to a large group of mammals known as artiodactyls, which recent fossil studies have suggested gave rise to whales news.nationalgeographic.com/news/2001/09/0919_walkingwhale.htmlThe land-dwelling Indohyus probably dove into streams to avoid predators, as seen in an artist's conception above.
Whale evolution return
A southern right whale and calf breach the ocean surface near South Africa, in this undated photo. A recent study indicates that a semiaquatic, raccoon-size mammal called Indohyus represents the ''missing link'' in the evolution of whales. The structure of the animal's skull and ear show Indohyus was closely related to whales, the study team said, adding that the density of its bones and the chemistry of its teeth suggest it spent much of its time in the water. But the crucial piece of evidence that would link the animal to whales is the ear bone covering the animal's middle ear, said Philip D. Gingerich, a University of Michigan paleontologist. Full analysis of the ear is missing in the new paper, he said. Gingerich thinks that more convincing information is needed than what is provided in the study.
In an artist's conception the ancient baleen whale Janjucetus hunderi attacks its next meal. Fossils of the new, flesh-eating species were recently found in Australia (inset).The discovery may rewrite the evolutionary history of baleen whales; all modern members of the group, which includes the enormous blue whales, are toothless giants that filter seawater for tiny krill and other creatures.
Humpback whales are known for their magical songs, which travel for great distances through the world's oceans. These sequences of moans, howls, cries, and other noises are quite complex and often continue for hours on end. Scientists are studying these sounds to decipher their meaning. It is most likely that humpbacks sing to communicate with others and to attract potential mates.These whales are found near coastlines, feeding on tiny shrimp-like krill, plankton, and small fish. Humpbacks migrate annually from summer feeding grounds near the poles to warmer winter breeding waters closer to the equator. Mothers and their young swim close together, often touching one another with their flippers with what appear to be gestures of affection. Females nurse their calves for almost a year, though it takes far longer than that for a humpback whale to reach full adulthood. Calves do not stop growing until they are ten years old.Humpbacks are powerful swimmers, and they use their massive tail fin, called a fluke, to propel themselves through the water and sometimes completely out of it. These whales, like others, regularly leap from the water, landing with a tremendous splash. Scientists aren't sure if this breaching behavior serves some purpose, such as cleaning pests from the whale's skin, or whether whales simply do it for fun.