You can find a good explanation of the (minor) issue on the same site, here. It's good science in action.

CTD is probably unaware that Dr. Hans Thewissen, whose site this is, was the discoverer of ambulocetus. He is an expert on the phylogeny of whales and also, curiously, on the origin and evolution of bats. Want to guess how much of his site CTD read before he made the above comments?