The skull is cetacean-like but its jawbones lack the enlarged space that is filled with fat or oil and used for receiving underwater sound in modern whales.
它的头骨与鲸类相似，但它的下颚骨没有现代鲸鱼用来接收水下声音的、充满脂肪或油脂的扩充空间。
Notice how the original jawbones interlock to form sturdy walls.
请注意下颚骨是如何联锁而形成坚墙的。
Collectors pay thousands of dollars for the jawbones of a shark.
