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

MYTH

While sharks have an excellent sense of smell, they can only detect blood from about a quarter mile away under ideal conditions.

Source: Shark Sensory Biology - Florida Museum

FACT

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

Source: Ancient Sharks - Natural History Museum

MYTH

Bull sharks can live in both salt and fresh water, and have been found hundreds of miles up rivers.

Source: Bull Sharks in Freshwater - National Geographic

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