The Life of Animals | Basilosaurus | Basilosaurus averaged about 18 meters (60 ft) in length, and is believed to have been the largest animal to have lived in its time It displayed an unparalleled degree of elongation compared with modern whales. Their very small vestigial hind limbs have also been a matter of interest for paleontologists. The species is the state fossil of Mississippi and Alabama in the United States.
Vertebrae were sent to the American Philosophical Society by a Judge Bly of Arkansas and Judge John Creagh of Clarke County, Alabama. With some reservation, Harlan speculated that the fossils belonged to a (50 m [166 ft] long) marine reptile, for which he suggested the name Basilosaurus, meaning “King reptile’’ Owen proposed renaming the find to Zeuglodon cetoides (“whale-like yoke teeth”), which is now a junior synonym; though the latter is considered by many to be a more fitting name, the first-published name always takes precedence. The name Zeuglodon refers to the double rooted teeth typical of marine mammals.
The remains were eventually destroyed in the Great Chicago Fire. In 1894 Smithsonian curator Charles Schuchert went to Alabama and collected fossil bones in order to mount the first scientifically accurate specimen. It is still on display today in the National Museum of Natural History, the only real specimen currently exhibited in the world There is a plaster cast on display in the Alabama Museum of Natural History. Fossil finds of another related species, Basilosaurus isis, have been found in the aptly named Valley of the Whales in Egypt. The fossils were very well preserved, hind limbs included, and were rather numerous. Paleontologist Philip Gingerich, who organized several expeditions to the valley, speculated that Egyptian crocodile worship may have been inspired by the huge skeletons that lay there. Fossil remains of another species, Basilosaurus drazindai, have been found in Pakistan. Another fossilized species named Basiloterus husseini was its closest known relative, but was not as large or elongated. Basilosaurus was highly elongated. It is also believed to have had unusual locomotion, compared with all other cetaceans; similarly sized thoracic, lumbar, sacral and caudal vertebrae imply that Basilosaurus moved in an anguilliform (eel-like) fashion, only vertically. Most reconstructions show a small, speculative dorsal fin similar to a rorqual whale’s, but other reconstructions show a dorsal ridge. The whale also possessed small, 0.6 meter (2 ft) hind limbs, which clearly cannot aid locomotion on a 15-22 meter (50-72 foot) animal. Judging from the relatively weak axial musculature and the thick bones in the limbs, The head of Basilosaurus did not have room for a melon like modern day toothed whales, and the brain was smaller in comparison as well.
