Resultado de búsqueda
Hippos likely evolved from a group of anthracotheres about 15 million years ago, the first whales evolved over 50 million years ago, and the ancestors of both these groups were terrestrial. These first whales, such as Pakicetus, were typical land animals. They had long skulls and large teeth that could be used for eating meat.
Blue whales are the largest animals to have ever existed. Learn why they're larger than any land animal and why they were hunted for years, making them endangered. Share Tweet Email.
Anatomy, Diversity & Evolution. Anatomy & Physiology. What Makes a Whale a Whale? Whales are mammals which means that, like humans and other land mammals, they have three inner ear bones and hair, they breathe air, and the females produce milk through mammary glands and suckle their young.
Whales range in size from the 2.6 metres (8.5 ft) and 135 kilograms (298 lb) dwarf sperm whale to the 29.9 metres (98 ft) and 190 tonnes (210 short tons) blue whale, which is the largest known animal that has ever lived. The sperm whale is the largest toothed predator on Earth.
Whales can be found inhabiting all of the world’s major oceans, from the Arctic and Antarctic oceans to the tropical waters in and around the equator’s center. Depending on species and migration patterns, some whales may be found particularly abundant in some locations while completely absent in others.
The common ancestor of whales and of all other land animals was a flatheaded, salamander-shaped tetrapod that hauled itself out of the sea onto some muddy bank about 360 million years ago.
1 de dic. de 2010 · In the space of just three decades, a flood of new fossils has filled in the gaps in our knowledge to turn the origin of whales into one of the best-documented examples of large-scale...
