Correct Option
The correct option isWhales
Explanation
The presence of marine fossils in the Sahara Desert serves as geological evidence that the region was once submerged under the Tethys Sea. This points to a past environment that was aquatic and significantly different from the current arid desert conditions.
Detailed Analysis
- Whales is Correct: The reference is specifically to the Wadi Al-Hitan (Valley of the Whales) in the Western Desert of Egypt. This UNESCO World Heritage site contains hundreds of fossil skeletons of the earliest suborder of whales, Archaeoceti. These fossils date back to the Eocene epoch (approximately 40 to 50 million years ago) and demonstrate that the Sahara was once a marine environment.
- Options Fish, Dolphins, and Seals are Incorrect: While fossils of other aquatic life (such as fish or turtles) may exist in various parts of the desert due to different geological or climatic phases (such as the "Green Sahara" period), the discovery of whale skeletons is the most prominent and distinct scientific finding used to illustrate the region's marine geological history in this context.
Key Takeaway
Wadi Al-Hitan in the Sahara Desert is famous for the discovery of whale fossils (Archaeoceti), proving that the desert was once the floor of the Tethys Sea.