Is it true that whales were once land animals?

Question

If so, did they look exactly the same but with legs? A walking blue whale must have been quite a sight- do we know what they looked like, are there any artists' impressions on the net? Thanks!

Answer 1

They weren't nearly as big as a blue whale - for the simple reason that the act of being on land is what limits an animal's maximum size.
The aqueous environment of the ocean is what has allowed cetaceans to be as large (which, they are the largest mammals to ever live) as they are.
They were probably more along the size (just size, not body shape or anything) of a small porpoise and had rudimentary legs (probably like Thrinaxadon et.al.) - before their legs (really, pectoral and pelvic girdles) had fully adapted to a terrestrial environment, though, they "back" evolved (so-to-speak) to living their life completely at sea.

Answer 2

This was a tricky problem for Darwin, but nevertheless he still had faith that whales evolved from land mammals. The paleontologist Phil Gingerich of the University of Michigan agrees that ‘it’s a real puzzle how whales originally evolved.’ But on this episode, he gives the impression that his fossil finds have gone a long way towards solving this puzzle. ‘Until now paleontologists thought whales had evolved from mesonychians, an extinct group of land-dwelling carnivores, while molecular scientists studying DNA were convinced they descended from artiodactyls [even-toed ungulates]. This serpentine and fully aquatic mammal has been known since the 19th century, but Gingerich discovered something new in some specimens in the Sahara Desert. The narrator pointed out that this area was under water once, and described a 100-mile stretch of layered sandstone called the ‘valley of the whales’, and allegedly 40 million years old. They theorize that it was a protected bay where whales came to give birth and to die. Gingerich discovered what he alleged were a pelvis, leg bones and a knee cap, so was evidence of ‘functioning legs’ and ‘dramatic proof that whales were once fully four-legged mammals.’ Another problem is that Basilosaurus has a number of features that mean it could not possibly have been ancestral to modern whales, e.g. body shape, skull structure and tooth shape.
There is certainly no support for the program’s claim, ‘front legs became fins, rear legs disappeared, bodies lost fur and took on their familiar streamlined shape’. Waving the magic wand of mutation/selection is hardly sufficient without an observable mechanism that would effect these changes. Marine mammals move through the water with vertical undulating movements of the spine, just as many fast-running mammals do on land. Fish move with sideways undulations instead. But this could be another common design feature of mammals, Tetrapods are animals with four limbs, i.e. amphibians, reptiles, birds and mammals. In 1995, Neil Shubin and Ted Daeschler found in Pennsylvanian cliffs a shoulder bone of a tetrapod allegedly 370 million years old.

Answer 3

The answer is No. The ancestors of whales are believed to have been land animals, but no theory holds that there were terrestrial whales. The evolutionary theories for whales & dolphins are based more on their anatomy, rather than fossil evidence because the fossil record is very incomplete for this lineage.

Whales & dolphins contain the same basic skeleton formation as land mammals, and little in common with fish. Also, some whale bones (such as the pelvic bone) really have no use in water - so, its logical that there must have been a terrestrial ancestor.

Answer 4

All cetaceans, including whales, dolphins and porpoises, are descendants of land-living mammals of the Artiodactyl order (even-toed ungulate animals). Both cetaceans and artiodactyl are now classified under the super-order Cetartiodactyla which includes both whales and hippos. In fact, whales are the closest living relatives of hippos; they evolved from a common ancestor at around 54 million years ago.
Whales entered the water roughly 50 million years ago

Answer 5

Yes, whales are mammals, which evolved on land.
Early mammals were quite small. I am not sure at what point they started going back to the sea; but there are a few different modern species which ancestors went to the sea.

Otters, Walrus, Seals, Dolphins and Whales are all mammals which went back to the sea at some point in their evolution.

Answer 6

Whales weren't but their ancestors were and as time went on they evolved a more piscine shape. The Blue whale is thought to be the largest animal to have ever lived but it would never have been the same size on land.

Answer 7

Well don't forget 'whales' is a term we use for modern ocean going cetaceans. Their ancestors were land animals but when you think that they're mammals and mammals evolved on land it shouldn't really be that surprising.

They evolved from some hoofed land animals, possibly the mesonychids. There are many transitional fossils that have been discovered and even modern whales have pelvic girdles.

A whale's fin has the same finger and wrist bones that you have.

http://en.wikipedia.org/wiki/Evolution_of_cetaceans
http://www.talkorigins.org/features/whales/
http://hometown.aol.com/darwinpage/landtosea.htm
http://www.neoucom.edu/DEPTS/ANAT/Thewissen/whale_origins/index.html
http://www.edwardtbabinski.us/babinski/whale_evolution.html
http://news.bbc.co.uk/1/hi/sci/tech/1974869.stm
http://news.bbc.co.uk/1/hi/sci/tech/4204021.stm

Answer 8

They evolved from an ancestor that was a land animal.

That ancestor was a four legged animal that started going into the water.

Eventually it began evolving into an animal only suited for living in the water.

Evolution takes millions of years.

The skeleton of a whale shows that the pectoral flippers have five fingers in them.

Whales still have vestigial hind leg bones inside them. They aren't attached and are near the reproductive organs. They have shrunk over millions of years, and still aren't completely gone.

Evolution is a very long gradual process. It's not as quick as just having a modern whale with actual legs.

Answer 9

Yes it is true. Archaeocetes is the earliest know whale. It is thought that Pakicetus is a transitional species. There are others as well.

Whale evolution
http://www.pbs.org/wgbh/evolution/library/03/4/l_034_05.html

The Origin of Whales and the Power of Independent Evidence
http://www.talkorigins.org/features/whales/

The Oldest Whales
http://www.ucmp.berkeley.edu/mammal/cetacea/cetacean.html

Answer 10

scout ambulocetus


the initial "whales" were large animals like crossbred weasel with an alligator.

check the bbc website at www.bbc.co.uk search for "walking with beasts" there is plenty of art relating ancient animals, including the whales