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
Captive killer whales water, and holding under water. Killer whales biting trainers during feeding or shows is generally the mildest form of attack seen, but can escalate to an animal dragging the trainer underwater and holding them there until they lose consciousness or drown. Trainers who have had killer whales ram into them in the water tend to suffer from a range of injuries including internal bleeding, broken bones, ruptured organs, and heart attack. Tilikum, a large bull male killer whale who died in early 2017, had been involved in the death of three individuals since his capture near Iceland in November 1983.