Whales are amazing creatures that have been swimming through the oceans for millions of years. What many people don’t realize, however, is that long before that, the ancestors of whales walked on land.

In an area in Egypt’s Western Desert, researchers found over 400 almost perfectly preserved skeletons of these whale ancestors. The area is known as Whale Valley, and some of these skeletons are from about 40 million years ago.

At that time in history, this part of what is now the Sahara Desert was covered by the Tethys Sea. It is in this area that it is believed that this is where the animals slowly evolved from being land dwelling to sea dwelling. The earliest suborder of whales known is called the archaeocetes, which is commonly considered the transitional species for whales.

In 2005, Whale Valley was named a UNESCO Heritage Site. During the announcement of its naming, a statement read:

“These fossils represent one of the major stories of evolution: the emergence of the whale as an ocean-going mammal from a previous life as a land-based animal. This is the most important site in the world for the demonstration of this stage of evolution. The fossils of Al-Hitan show the youngest archaeocetes, in the last stages of losing their hind limbs. They already display the typical streamlined body form of modern whales, whilst retaining certain primitive aspects of skull and tooth structure.”

Having access to all of these bones has helped scientists to learn a lot more about the history of whales and how they evolved to become the largest animals ever to exist on the planet. They could never have gotten so big on land, so it is a good thing for them that they decided to make the journey into the water.

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