How the Walrus Got Its Tusks

The rise and fall of ancient walruses, and how modern ones got their tusks, is a story that spans almost 20 million years. And while there are parts of the story that we’re still trying to figure out, it looks like tusks didn’t have anything to do with how or what these animals ate.

Season 3 Episode 12 Length 07:42 Premiere: 07/29/20

Recent Episodes

Did Ancient Storms Kill These Pterosaurs?

S8 E13 Length 10:05 Premiere Date 03/17/26

Sensitive Teeth? Blame This Fish

S8 E12 Length 11:08 Premiere Date 03/03/26

The Fiery Rise of Flowering Plants

S8 E11 Length 10:45 Premiere Date 02/10/26

When Ancient Weeds Fooled Us

S8 E10 Length 11:37 Premiere Date 01/27/26

How Brawn Led to Brains

S8 E9 Length 12:14 Premiere Date 01/13/26

When a Tiny Land Bridge Triggered an Ice Age

S8 E8 Length 10:27 Premiere Date 12/17/25

Specials

When Dinosaurs Threw Up A Mystery

Length 09:15 Premiere Date 07/22/25

Did Dinosaurs' Extinction Give Us Fruit?

Length 10:47 Premiere Date 07/15/25

Why Paleontologists Can’t Stop Fighting About Spinosaurus

Length 08:37 Premiere Date 07/01/25

The Dinosaurs Too Big To Be Dinosaurs

Length 12:22 Premiere Date 06/17/25

Season 3 Episodes

Show Episodes

Show Clips & Previews

Where Are All The Squid Fossils?

S3 E45 Length 07:21 Premiere Date 06/03/21

How Weasels Got Skinny

S3 E44 Length 09:01 Premiere Date 05/18/21

When Trees Took Over the World

S3 E43 Length 07:28 Premiere Date 05/12/21

How To Survive the Little Ice Age

S3 E42 Length 10:00 Premiere Date 04/20/21

When Crocs Thrived in the Seas

S3 E41 Length 09:08 Premiere Date 04/27/21

How Chilis Got Spicy (and Why We Love the Burn)

S3 E40 Length 09:32 Premiere Date 04/06/21

How Humans Became (Mostly) Right-Handed

S3 E39 Length 08:36 Premiere Date 03/24/21

How Worm Holes Ended Wormworld

S3 E38 Length 09:42 Premiere Date 03/18/21

Our Bizarre, Possibly Venomous, Relative

S3 E37 Length 08:11 Premiere Date 03/10/21

The Genes We Lost Along the Way

S3 E36 Length 12:01 Premiere Date 02/24/21

The Return of Giant Skin-Shell Sea Turtles

S3 E35 Length 06:53 Premiere Date 02/17/21

When We First Talked

S3 E34 Length 11:13 Premiere Date 02/11/21

The Pandemic That Lasted 15 Million Years

S3 E33 Length 09:20 Premiere Date 01/28/21

The Reign of the Hell Ants

S3 E32 Length 10:09 Premiere Date 01/21/21

The Bear-Sized Beaver That Couldn’t Build A Dam

S3 E31 Length 07:32 Premiere Date 01/13/21

The Triassic Reptile With "Two Faces"

S3 E30 Length 10:11 Premiere Date 12/22/20

When the Earth Suddenly Stopped Warming

S3 E29 Length 10:21 Premiere Date 12/17/20

When Lizards Took Over the World

S3 E28 Length 08:29 Premiere Date 12/09/20

How Humans Lost Their Fur

S3 E27 Length 11:27 Premiere Date 12/02/20

The Rise and Fall of the Tallest Mammal to Walk the Earth

S3 E26 Length 07:53 Premiere Date 11/17/20

How Plankton Created A Bizarre Giant of the Seas

S3 E25 Length 08:48 Premiere Date 11/10/20

Why Do Things Keep Evolving Into Crabs?

S3 E24 Length 06:46 Premiere Date 10/28/20

How Ankylosaurs Got Their Clubs

S3 E23 Length 07:52 Premiere Date 10/13/20

How Plants Became Carnivores

S3 E22 Length 09:48 Premiere Date 10/07/20

What Happened To Primates In North America?

S3 E21 Length 08:54 Premiere Date 09/30/20

Why Did These Ancient Gophers Have Horns?

S3 E20 Length 08:23 Premiere Date 09/15/20

The Sea Monster from the Andes

S3 E19 Length 06:27 Premiere Date 09/10/20

How Ancient Art Captured Australian Megafauna

S3 E18 Length 09:43 Premiere Date 09/02/20

The Oddest Couple in the Fossil Record

S3 E17 Length 08:48 Premiere Date 08/20/20

How We Figured Out Fermentation

S3 E16 Length 09:20 Premiere Date 08/13/20

The Dinosaur Who Was Buried at Sea

S3 E15 Length 12:11 Premiere Date 08/05/20

The Biggest Frog that Ever Lived

S3 E14 Length 07:05 Premiere Date 07/23/20

The Story of the Dino Stampede

S3 E13 Length 10:43 Premiere Date 07/16/20