Anatomy of skull and mandible

Abstract The skull of the bowhead whale is composed of all the bones commonly found in mammals, although the shape of these bones is far from ordinary. Features related to feeding dominate the skull: there are no teeth, and the rostrum is long and curved, resembling a bow. The incisive and maxilla form a high arch that forms the origin of the baleen rack, and the mandibles are straight in lateral view, but deeply curved in the horizontal plane to make room for the tongue and baleen. The blowhole is located near the apex of the skull, and the boney portion of the nasal passage opens caudally into the nasopharynx ventral to the braincase. As in other baleen whales, the occipital projects rostrally, covering a portion of the parietals and frontals.