Evolution of cetaceans "Caperea marginata") all have derived characteristics presently unknown in any cetothere and vice versa (such as a sagittal crest). The adaptation of echolocation occurred when toothed whales (Odontoceti) split apart from baleen whales, and distinguishes modern toothed whales from fully aquatic archaeocetes. This happened around 34 million years ago in a second cetacean radiation. Modern toothed whales do not rely on their sense of sight, but rather on their sonar to hunt prey. Echolocation also allowed toothed whales to dive deeper in search of food, with light no longer necessary for navigation, which opened up new food sources. Toothed whales
Greater white-toothed shrew but otherwise very similar, and can often be distinguished only by close inspection of its teeth which are unpigmented. The greater white-toothed shrew is distinguished by a careful examination of their unpigmented teeth. Like other "white toothed-shrews", "C. russula" lacks the deposition of iron in their enamel at the tips of their teeth This particular species has a greyish or reddish brown upper coat with a yellowish grey coat in the underside The greater white-toothed shrews are part of the medium-sized shrews and weigh around 11 grams to 14 grams The head and body length of "C. russula" is about