However, publications since then not only lead to some major changes of the internal relationships within Basilosauridae but have also called into question how diagnostic elongated vertebrae are for members of this group, as other early whales have developed similar anatomy independently.

Gingerich and colleagues tentatively refer a vertebral centrum from the Barton Group of England to this genus as well on the basis of its age, size and general morphology.

The species name of Basiloterus husseini honors Dr. S. Taseer Hussain, a researcher who warked at the Howard University in Washington DC and sponsored the first expedition to the Drazinda Formation.

[1] Gingerich and colleagues considered Basiloterus to be a close relative of Basilosaurus based on the size and shape of the lumbar vertebrae as well as the fact that the two genera were contemporary.

[3] †Pakicetidae †Ambulocetidae †Remingtonocetidae †Protocetidae †Cynthiacetus †Basiloterus †Basilosaurus †Dorudon †Ancalecetus †Zygorhiza †Saghacetus †Chrysocetus Mysticeti Odontoceti The elongation of the vertebrae as a convergent trait is again noted by Gol'din and Zvonok, who propose that it had been independently gained by Basiloterus, Basilotritus and Basilosaurus.

They argue that this independent acquisition of elongated lumbars renders it an unreliable character to separate the subfamilies Basilosaurinae and Dorudontinae, further supported by the close relationship they recover between Basilosaurus and Dorudon.

[2] Similar results also appear in later papers such as the description of the small-bodied basilosaurid Tutcetus, which also argues against the concept of a distinct Basilosaurinae and Dorudontinae and does not discuss Basiloterus.

[7] The description of Cynthiacetus peruvianus also fails to recover two distinct subfamilies and simply refers to Basiloterus as a basilosaurid of uncertain relation to the other taxa within the family.

[4] Although not found in the same area, Basiloterus likely coexisted with Basilosaurus drazindai as they both come from the same green shales of the Drazinda Formation,[1] which also yielded the remains of the giant softshell turtle Drazinderetes.