How would you explain the evolutionary history of the whale?
Unlike the hippo’s ancestor, whale ancestors moved to the sea and evolved into swimming creatures over a period of about 8 million years. Fossils of gigantic ancient whales called Basilosaurus were first mistaken for dinasaur fossils but were later recognised as mammals.
What are two things that fossils of whales tell us about whale evolution?
Starting in the late 1970s, a growing number of fossils have allowed scientists to piece together the story of whale evolution. The fossils represent ancient, whale-like animals. They show that an ancient land mammal made its way back to the sea more than 50 million years ago. It became the ancestor of modern whales.
How does a whale become a fossil?
Fossils are preserved remains of plants and animals that lived thousands to millions of years ago. Fossil remains indicate that whales evolved from hoofed land animals.
What was the first evolution of a whale?
The Origin of Whales or the Evolution. The first whales appeared 50 million years ago, well after the extinction of the dinosaurs, but well before the appearance of the first humans. Their ancestor is most likely an ancient artiodactyl, i.e. a four-legged, even-toed hoofed (ungulate) land mammal, adapted for running.
Why did whales evolve to live back in the ocean?
Vertebrates evolved in the sea and eventually moved onto land. The ancestors of whales later returned to the sea, taking advantage of its rich food supplies. As early whales adapted to their new marine surroundings, a diversity of species evolved.
What did fossils teach us about whales?
The fossils help reveal the whale’s deep history, from extinct species that originally lived on land to today’s cetaceans. And by knowing their past we can help ensure that these magnificent creatures survive the many threats they face in today’s world.
Were whales land creatures?
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.
How did whales lose?
In findings to be published this week in the Proceedings of the National Academy of Sciences, scientists say the gradual shrinkage of the whales’ hind limbs over 15 million years was the result of slowly accumulated genetic changes that influenced the size of the limbs and that these changes happened sometime late in …