Toothed whale whales do not have wax ester deposits nor branched fatty chain acids in their blubber. Thus, more recent evolution of these complex blubber traits occurred after baleen whales and toothed whales split, and only in the toothed whale lineage. Toothed whales have torpedo-shaped bodies with inflexible necks, limbs modified into flippers, nonexistent external ear flaps, a large tail fin, and bulbous heads (with the exception of sperm whales). Their skulls have small eye orbits, long beaks (with the exception sperm whales), and eyes placed on the sides of their heads. Toothed whales range in size from the and vaquita to
White-toothed woodrat data provided by Macedo and Mares (1988) for what was then thought to be a single species applies to both. White-toothed woodrat Neotoma leucodon is a species of rodent in the family Cricetidae. Although originally named from San Luis Potosí, Mexico, as a species by Merriam, the white-toothed woodrat was long considered to be a synonym of the white-throated woodrat ("Neotoma albigula"). Molecular data, however, indicate the populations east of the Rio Grande in New Mexico and Trans-Pecos Texas represent a different species than morphologically similar populations west of the river. The habitat preferences of the two species appear similar,