These teeth push through the gums sooner in males than in females and often never erupt in the latter sex. There also are frequently series of small nonfunctional teeth in the upper and lower jaws. Except in Berardius, the bones of the skull are asymmetrical. Certain cranial bones are crested or elevated, forming large ridges in Hyperoodon and lesser ridges in some of the other genera. There are 43-49 vertebrae, and those of the neck tend to fuse.
Beaked whales are the least known of cetacean families.
They usually remain well out to sea, avoid ships, and dive to great depths to secure cephalopods and fish. Some appear to be solitary, some travel in groups of 2-12, and some, particularly Ziphius, associate in schools of 40 or more. They generally swim and dive in unison. The hides of many individuals are scratched from intraspecific fighting. The newborn are about one-third as long as the mother.