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
Double-toothed barbet the seeds of some fruits. These barbets can be found in pairs or small family groups with helpers; lone double-toothed barbets are rare. Their territories are large. Double-toothed barbets roost communally, as all the barbets in a group roost in the same hole. Nests are made by excavating a tree, often rotting, at above two meters. Both barbets in a pair will dig out the nesting hole, and both will defend it. The entrance the nest is circular, five or more centimeters across. Some nests have an entrance tunnel. At maximum, a nest is 46 centimeters deep. When a male