In 1996, Thewissen and two others published "Ambulocetus natans, an Eocene cetacean (Mammalia) from Pakistan" in Courier Forschungsinstitut Senckenberg, a peer-reviewed journal. That's as far as I can go, since I don't read German, but it's a good bet that that's where they "described" the pelvis. SIX YEARS before Batten's addendum tries to wave away the evidence

Well, then what is this all about?

Journal of Vertebrate Paleontology

Article: pp. 405–422 | Abstract | PDF (2.24M)

Additional holotype remains of Ambulocetus natans (Cetacea, Ambulocetidae), and their implications for locomotion in early whales

S. I. MADAR^A, J. G. M. THEWISSEN^B, and S. T. HUSSAIN^C

A. Department of Biology, Hiram College, Hiram, Ohio 44234, E-mail: madarsi@hiram.edu, B. Department of Anatomy, Northeastern Ohio Universities College of Medicine, 4209 State Route 44, Rootstown, Ohio 44272, E-mail: thewisse@neoucom.edu, C. Department of Anatomy, Howard University, 520 W Street, Washington, D.C. 20059

Continued excavation at the type locality of Ambulocetus natans led to the recovery of a majority of the axial skeleton of the holotype of this early Eocene cetacean, including both innominates, the sacrum, and most of the thoracic cage and thoracolumbar vertebral column. Additional appendicular, caudal, and cranial materials were also recovered, resulting in a specimen that is now approximately 80 percent complete. This new material allows refined interpretations of its functional morphology. Ambulocetus has a longer thoracolumbar column than that reported for later remingtonocetid and protocetid genera, suggesting that previous estimates of spinal length derived from models of mesonychid ancestry may be inaccurate. Ambulocetus also possesses a co-ossified ecto–mesocuneiform, a character found in some early and middle Eocene artiodactyls, but not mesonychids. New postcranial material provides further evidence of a systemic shift to aquatic locomotion.

Received: October 6, 2000; Accepted: June 16, 2001

DOI: 10.1671/0272-4634(2002)022[0405:AHROAN]2.0.CO;2