A comparison of the third molars from three species of Pakicetus as viewed from the back. (From Cooper et al., 2009)

Crack open just about any recent popular overview of evolution (namely Why Evolution is True, The Greatest Show on Earth, and Evolution: What the Fossils Say and Why it Matters) and somewhere inside you will find a string of skeletal whales. Starting with either Indohyus or Pakicetus, the illustration will feature a graded series of forms that connect modern whales with their terrestrial ancestors. A caveat may be included in the text to say that we cannot be absolutely sure that each included genus gave rise to the next, but the general