‘Waterworld’ Earth preceded late rise of continents, scientist proposes
Expansion of dry land may have enabled Cambrian explosion
![ocean](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2016/12/121916_TS_waterworld_main.jpg?fit=860%2C460&ssl=1)
WATER WORLD The continents rose above sea level only a few hundred million years ago, a new proposal states. Before that time, Earth’s surface was mostly covered by water.
Tfioreze/Wikimedia Commons (CC BY-SA 3.0)