FACT

Sharks can lose and regrow thousands of teeth in their lifetime, with some species growing new teeth every two weeks.

Source: Shark Teeth Facts - American Museum of Natural History

FACT

Sharks first appeared around 400 million years ago, while dinosaurs appeared around 230 million years ago.

Source: Ancient Sharks - Natural History Museum

MYTH

Sharks don't sleep in the traditional sense, but they do have periods of rest and reduced activity.

Source: Do Sharks Sleep? - Discovery Channel

MYTH

While rare, sharks can and do get cancer. This misconception led to harmful cartilage supplement marketing.

Source: Do Sharks Get Cancer? - Journal of Cancer Research

FACT

Sharks have special organs called ampullae of Lorenzini that can detect the electrical fields of other animals.

Source: Shark Magnetic Navigation - Current Biology