A complete "Basilosaurus" skeleton was found in 2015, and several attempts have been made to reconstruct the vertebral column from partial skeletons. estimated a total of 58 vertebrae, based on two partial and nonoverlapping skeletons of "B. cetoides" from Alabama. More complete fossils uncovered in Egypt in the 1990s allowed a more accurate estimation: the vertebral column of "B. isis" has been reconstructed from three overlapping skeletons to a total of 70 vertebrae with a vertebral formula interpreted as seven cervical, 18 thoracic, 20 lumbar and sacral, and 25 caudal vertebrae. The vertebral formula of "B. cetoides" can be assumed to be the same.