Narrator: Lions have them, hippos have them, and even you and I have them: canines, those long, pointy front teeth. They're actually the longest teeth in the human mouth. So what are these long, sharp ...

Tens of million years ago, sand tiger sharks hunted in the waters off the Antarctic Peninsula, gliding over a thriving marine ecosystem on the seafloor below. All that remains of them today is their ...

Tens of million years ago, sand tiger sharks hunted in the waters off the Antarctic Peninsula, gliding over a thriving marine ecosystem on the seafloor below. All that remains of them today is their ...