Book 16, Question 19
Why Do Fossils of Sea Creatures Turn Up in Some Deserts?
Parts of some deserts used to lie under warm, shallow seas millions of years ago! Shells and sea animals sank into the mud, and the mud hardened into rock. Later the sea went away and left the fossils behind.
More fun facts
- Wadi Al-Hitan, which means Whale Valley, lies in the Western Desert of Egypt.
- It holds fossils of early whales called archaeocetes, many as complete skeletons.
- About 40 million years ago, much of North Africa lay under a shallow ocean called the Tethys.
- The whale fossils there are about 37 to 40 million years old.
- Some Basilosaurus skeletons there still have tiny hind legs with thigh bones, ankles, and little feet.
- Visitors can also spot mollusc shells and shark teeth in the sand.
Sources: whc.unesco.org, National Geographic
Questions kids ask
Why did whales have legs?
Whales came from animals that lived on land, and their legs shrank as they adapted to life in the sea.