Toothed whale porpoise as a fish. Toothed whales, as well as baleen whales, are descendants of land-dwelling mammals of the artiodactyl order (even-toed ungulates). They are closely related to the hippopotamus, sharing a common ancestor that lived around 54 million years ago (mya). The primitive cetaceans, or archaeocetes, first took to the sea approximately 49 mya and became fully aquatic by 5–10 million years later. The adaptation of echolocation and enhanced fat synthesis in blubber occurred when toothed whales split apart from baleen whales, and distinguishes modern toothed whales from fully aquatic archaeocetes. This happened around 34 mya. Unlike toothed whales, baleen
Smooth-toothed pocket gopher move the traps. Toxic bait can also be used, but involves a different trap placement strategy. Fumigation is usually unsuccessful because gophers can quickly seal off their burrows at the first whiff of fumes. The exception to this is fumigation with aluminum phosphide; however, this can only be used by a professional. Gas explosives and flooding have commonly been utilized to force gophers from their burrows, and while sometimes successful, are not guaranteed to achieve full eradication. Smooth-toothed pocket gopher The smooth-toothed pocket gophers, genus Thomomys, are so called because they are among the only pocket gophers without grooves on