Wadi Al-Hitan, or “Whale Valley,” is a UNESCO World Heritage Site in the Western Desert of Egypt. It is indeed a location where a multitude of fossils from the Eocene epoch (approximately 40 million years ago) have been found. The most significant finds are the skeletons of Archaeoceti, the earliest, now-extinct suborder of whales. These fossils have provided invaluable evidence of the evolutionary transition of whales from land-based mammals to fully marine animals.

The largest and most common of these fossils is the Basilosaurus, an immense, serpentine-shaped ancient whale that reached up to 60 feet in length. Its size and somewhat monstrous appearance have led to it being colloquially referred to as a “leviathan” in popular media and by some researchers, but this is a nickname, not its official scientific designation.

The dramatic claim in the headline is a reference to the spectacular reality of the fossil site. The fossils, including those of Basilosaurus, are so well-preserved and concentrated that they appear to be “unearthing Egypt’s ancient ocean” itself. The discovery of these giant, primitive whales with hind limbs has truly reshaped our understanding of evolution and the planet’s history.