Answer:
The area once contained water.
Explanation:
Fish do not have the anatomical structures necessary for breathing on land. Â Even if they did, they would likely desiccate in the arid environment of the desert. Â The same reasoning applies to seashells. Â As a result, the environment must have been different in order to support the needs of these creatures. Â Since the Earth's continents are continuously shifting due to plate tectonics, and the Earth's climate changes over time, it would be reasonable to say that the desert was once a body of water that could support marine life.