Modern cetaceans have internal, rudimentary hind limbs, such as reduced femurs, fibulas, and tibias, and a pelvic girdle. "Indohyus" has a thickened ectotympanic internal lip of the ear bone. This feature compares directly to that of modern cetaceans. Another similar feature was the composition of the teeth, which contained mostly calcium phosphate which is needed for eating and drinking by aquatic animals, though, unlike modern day toothed whales, they had a heterodont (more than one tooth morphology) dentition as opposed to a homodont (one tooth morphology present) dentition. Although they somewhat resembled a wolf, the fossils of pakicetids showed the eye sockets were much closer to the top of their head than that of other terrestrial mammals, but similar to the structure of the eyes in cetaceans. Their transition from land to water led to reshaping of the skull and food processing equipment because the eating habits were changing. The change in position of the eyes and limb bones is associated with the pakicetids becoming waders. The ambulocetids also began to develop long snouts, which is seen in current cetaceans. Their limbs (and hypothesized movement) were very similar to otters.