Portal:Cetaceans/Did you know

...whales and dolphins don’t sleep in the way humans do. Although we don’t know how they sleep, some scientists believe they sleep with half the brain asleep and half the brain awake, keeping them aware of danger.
...there are probably types of cetaceans that are as yet unknown. For example, the Longman's beaked whale is only known from skulls washed ashore in Somalia and Australia. It has never been seen alive!
...all whales and dolphins have the remains of the pelvis, but it is reduced to two small bones at the rear of the animal.
...the ‘strapped-toothed whale’ whale is so called because in mature males there are only two teeth in the bottom jaw and these completely ‘strap’ the upper jaw, preventing it from opening more than a few centimetres. How these animals eat is unknown, but it may be that they stun their prey with high intensity sound.
...some cetaceans can dive to depths of more than a kilometre and stay there for more than an hour.