The whale is named "Basilosaurus" because when its bones were first discovered in 1843, was incorrectly identified as a marine reptile.
Basilosaurus was 18-21 meters (60-70 ft) long and a short head with narrow snout. It did not have a blow hole like modern whales and would come to the surface to breath by raising the tip of its nose out of the water. The body of Basilosaurus was extremely long and slender. It also had smaller hind flippers.