Cetacea toothed whales and two in baleen whales. The nostrils are located on top of the head above the eyes so that the rest of the body can remain submerged while surfacing for air. The back of the skull is significantly shortened and deformed. By shifting the nostrils to the top of the head, the nasal passages extend perpendicularly through the skull. The teeth or baleen in the upper jaw sit exclusively on the maxilla. The braincase is concentrated through the nasal passage to the front and is correspondingly higher, with individual cranial bones that overlap. In toothed whales, connective tissue
Toothed belt slippage, and are often used to transfer motion for indexing or timing purposes (hence their name). They are often used in lieu of chains or gears, so there is less noise and a lubrication bath is not necessary. Toothed belts are used widely in mechanical devices, including sewing machines, photocopiers and many others. A major use of toothed belts is as the timing belt used to drive the camshafts within an automobile or motorcycle engine. As toothed belts can deliver more power than a friction-drive belt, they are used for high-power transmissions. These include the primary drive of some motorcycles,