2013年3月6日 · One such “walking whale” is Ambulocetus (am-bew-lo-SEAT-us) natans, which lived about 49 million years ago in what is now northern Pakistan, in long-lost coastal shallow seas and brackish rivers. This model of Ambulocetus natans, an Eocene "walking" whale that lived nearly 50 million years ago, was featured in the Museum exhibition Extreme Mammals.