Gazelle : The Palestinian Biological Bulletin (ISSN 0178 – 6288) . Number 134, February 2016, pp. 1-44. | Page 9

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Basilosaurus has an anguilliform (eel-like) body shape because of the elongation
of the centra of the thoracic through anterior caudal vertebrae. In life, these
vertebrae were filled with marrow, and, because of the enlarged size, this made
them buoyant. From this it can be deduced that Basilosaurus swam
predominantly in two dimensions at the sea surface, in contrast to the smaller
Dorudon which was probably a diving, three-dimensional swimmer. The skeletal
anatomy of the tail suggests that a small fluke was probably present, which
would have aided only vertical motion. Most reconstructions show a small,
speculative dorsal fin similar to a rorqual whales, but other reconstructions show
a dorsal ridge (Wikipedia).

Prof. Dr. Sc. Norman Ali Bassam Ali Taher Khalaf-von Jaffa studying a Basilosaurus isis
Whale Fossil at Wadi El-Hitan (Whales Valley), Al-Fayyum, Al-Sahraa Al-Gharbiah
(Western Desert), Egypt. Photo: Ola Mostafa Khalaf. 11.07.2012.
https://www.flickr.com/photos/50022881@N00/15470898485/

Hind Limbs
A 16 m (52 feet) individual of Basilosaurus isis had 35 cm (14 in) long 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, makes a locomotory function
Gazelle : The Palestinian Biological Bulletin – Number 134 – February 2016