page_title: Basilosaurus
section_title: Hind limbs
hierarchical_section_title: Basilosaurus / Description / Hind limbs
caption_attribution_description: English: Fossil of Basilosaurus, an extinct whale. Took the photo at Museum Histoire Naturelle, Paris
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: A 16-meter (52 ft) individual of B. isis had 35-centimeter-long (14 in) hind limbs with fused tarsals and only three digits. The limited size of the limb and the absence of an articulation with the sacral vertebrae make a locomotory function unlikely. Analysis has shown that the reduced limbs could rapidly adduct between only two positions. Possible uses for the structure have been given, such as clasper-like body functions. These limbs would have been used to guide the animals' long bodies during mating.
caption: B. isis hind limb
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