page_title: Basilosaurus
section_title: Wadi El Hitan
hierarchical_section_title: Basilosaurus / Taxonomic history / Wadi El Hitan
caption_attribution_description: Français&#160;: Moulage du squelette fossile de Basilosaurus isis, au Museum d'Histoire Naturelle de Nantes.
context_page_description: Basilosaurus is a genus of large, predatory, prehistoric archaeocete whale from the late Eocene, approximately 41.3 to 33.9 million years ago. First described in 1834, it was the first archaeocete and prehistoric whale known to science. The first fossils were discovered along the Gulf Coast of the United States, along with a few fossils in the eastern U.S., attributed to the type species B. cetoides. They were originally thought to be of a giant reptile, hence the suffix "-saurus", Ancient Greek for "lizard". The animal was later found to be an early marine mammal, which prompted attempts at renaming the creature, which failed as zoological nomenclature dictates using the original name given. Fossils were later found of the second species, B. isis, in 1904 in North Africa, more specifically the countries of Egypt, Jordan, Tunisia and Morocco. Basilosaurus has a possible record in Seymour Island in Antarctica.
  Basilosaurus is considered to have been common in the Tethys sea.
  It was one of the largest, if not the largest, animals of the Paleogene.
context_section_description: Wadi El Hitan, Arabic وادي الحيتان , "Valley of the Whales", is an Egyptian sandstone formation where many early-whale skeletons were discovered. German botanist Georg August Schweinfurth discovered the first archaeocete whale in Egypt (Zeuglodon osiris, now Saghacetus osiris) in 1879. He visited the Qasr el Sagha Formation in 1884 and 1886 and missed the now famous Wadi El Hitan by a few kilometers. German paleontologist Wilhelm Barnim Dames described the material, including the type specimen of Z. osiris, a well-preserved dentary.
  Hugh Beadnell, head of the Geological Survey of Egypt 1896–1906, named and described Zeuglodon isis in Andrews 1904 based on a partial mandible and several vertebrae from Wadi El Hitan in Egypt. Andrews 1906 described a skull and some vertebrae of a smaller archaeocete and named it Prozeuglodon atrox, now known today as Dorudon atrox. Kellogg 1936 discovered deciduous teeth in this skull and it was then believed to be a juvenile [Pro]zeuglodon isis for decades before more complete fossils of mature Dorudon were discovered.
  In the 1980s, Elwyn L. Simons and Philip D. Gingerich started to excavate at Qasr el-Sagha and Wadi El Hitan with the hope of finding material that could match archaeocete fossils from Pakistan. Since then, over 500 archaeocete skeletons have been found at these two locations, of which most are B. isis or D. atrox, several of the latter carrying bite marks assumed to be from the former. A 1990 paper described additional fossils including foot bones and speculated that the reduced hind limbs were used as copulatory guides. One thing that was noted, was that whale fossils were so common, that when a mason company looked at their newest table counter, they realized that they had created a cross section of a 40 million year old Basilosaurid fossil. This find was another thing that caught the eye of Gingerich.
  In 2016, a complete skeleton, the first-ever find for Basilosaurus, was uncovered in Wadi El Hitan, preserved with the remains of its prey, including a Dorudon and several species of fish. The whale's skeleton also shows signs of scavenging or predation by large sharks such as the otodontid Carcharocles sokolovi.
caption: Basilosaurus isis fossil, Nantes History Museum in France
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