Wādī al-Ḥītān is a paleontological site located in the governorate of Fayyūm, in the western desert of Egypt, about 150 km southwest of Cairo. In 2005 it was included in the list of UNESCO World Heritage Sites due to the presence in the area of hundreds of fossils of archaeocetes, ancient ancestors of today's whales, which lived during the geological era of the Eocene.
The site provides evidence to explain one of the greatest mysteries about cetacean evolution: how whales became marine mammals by evolving from terrestrial progenitors. Nowhere else is it possible to find such a high number of these fossils, both in quantity and concentration, of such high quality and inserted in an accessible, attractive and protected landscape.
Fossil whales were first discovered during the winter of 1902
In the valley, among the fossils that emerged from the erosion of the sandstones formed by the ancient seabed, over 500 skeletons of archaeocetes, complete or partial, have been documented and three different species of these ancient cetaceans have been identified.
The largest specimen is a 21 meter long Basilosaurus isis, a carnivorous cetacean with serrated teeth, fingered hind limbs and a tapered body like today's whales. The remains of these hidden arts testify to the evolution of cetaceans from terrestrial life forms to marine life forms. During the 2015 excavation campaign, the first and only known complete skeleton of Basilosaurus isis was found, 18 meters long, thanks to which it was possible to observe for the first time the tail equipped with spines (as in a thagomizer). Inside, the specimen still kept, at the stomach, the remains of the last meal: crabs, sawfish and a small cetacean. Alongside the skeleton, the presence of numerous shark teeth testifies to how the carcass was partially devoured after death and reflects the abundance of these species at the time.
Numerous skeletons of Dorudon atrox have also been found, archaeocetes up to 5 meters long, half of them very young, which suggests that the area represented a usual place for the birth of the young, favored by the shallow waters located along the southern coasts. of the Ocean of Tethys. Some skulls of Dorudon atrox's young show bite marks from a large predator, probably Basilosaurus isis.
A third species of archaeocetes is represented by the Ancalecetus simonsi, comparable in size to Dorudon atrox, of which only one partial skeleton has been found.
The presence of fossil remains of other marine animals including three primitive species of sirenids, remains of the Moeritherium, an ancestor of the elephant, crocodiles, sharks, sawfish, rays, bony fish, turtles and sea snakes, allows to reconstruct the ecological and environmental conditions of the area at the time of the evolution of archaeocetes.
The fossils also include numerous invertebrates: molluscs, gastropods, echinoids, bivalves and crabs.
There are only 1 000 visitors a year who travel to Wādī al-Ḥītān with 4WD as the track is unpaved and crosses desert sands. For the most part, visitors to Wādī al-Ḥītān are foreigners who routinely frequent the valley on winter weekends. As Wādī al-Ḥītān is within the protected area of Wādī al-Rayān, the site's conservation program channels visitors along a prescribed route. Sustainable tourism is beginning to develop and grow in the area, while visits aboard four-wheel drive vehicles are alternately replaced by walks or dromedaries.
About 40 to 37 million years ago, the Wādī al-Rayān area was under a large ocean called Tethys and this site was a beach and lagoon with mangrove vegetation. Three formations dating back to this period are visible in Wādī al-Rayān: Gahannam, Birket Qārūn and Qaṣr al-Ṣāgha. The Gahannam formation dates back to about 41-40 million years ago (Bartonian and Priabonian) and is composed of white marly limestone and chalky clay; together with the Birket Qārūn formation, dating back to the early Eocene, it contains most of the remains of marine animals (archaeocetes, sharks, chelonids, crocodiles). The formation of Qaṣr al-Ṣāgha is the most recent, dating back to about 39 million years ago (high Priabonian); it is exposed in some upper parts of the valley and, thanks to its wealth of invertebrate marine fauna, indicates a shallow marine environment.
Since a part of Wādī al-Ḥītān has been transformed into a tourist place, some walkways have been set up to connect the places where the main fossils are found and also small shelters have been built. This public park is now regularly visited by tourist groups and there is also a small campsite.
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