The skeleton is incomplete, with critical parts missing. It is also highly fragmented. To establish hind leg function it is necessary to have the pelvic girdle to demonstrate that the leg bones (femur and small proximal piece of tibia) belong to the rest of the skeleton and to determine muscle attachments. The pelvic girdle is missing!
With the forelimbs, the humerus and scapula are missing which are again crucial to interpreting function, as well as establishing connectedness to the skeleton.
Furthermore, this one caudal vertebra was not even found with the rest of the skeleton, being ‘referred material’, found 5 metres above. In other words, the whole of the lumbar, pelvic and caudal parts of Ambulocetus were ‘constructed’ from just one lumbar vertebra, one femur, a small piece of tibia (no fibula, no pelvis), a small piece of the ball of the ankle joint and a few foot and toe bones. And yet a detailed description is given of how the animal moved in water and on land!
Guess what dumbass it isn't even Ambulocetus that we are discussing. You cut and pasted some Bible-thumper's argument about an entirely different fossil. Nice argument, sorry it's irrelevant though!