Season 1

    Video thumbnail: Eons When Sharks Swam the Great Plains

    Eons

    When Sharks Swam the Great Plains

    When Sharks Swam the Great Plains

    When Sharks Swam the Great Plains

    Video thumbnail: Eons How Sloths Went From the Seas to the Trees

    Eons

    How Sloths Went From the Seas to the Trees

    The story of sloths is one of astounding ecological variability.

    How Sloths Went From the Seas to the Trees

    Video thumbnail: Eons When Camels Roamed North America

    Eons

    When Camels Roamed North America

    Camels' origins story begins in an environment you’d never expect: a rainforest.

    When Camels Roamed North America

    Video thumbnail: Eons When Birds Stopped Flying

    Eons

    When Birds Stopped Flying

    For birds that can't fly, how did Ratites end up all over the world?

    When Birds Stopped Flying

    Video thumbnail: Eons When Rodents Rafted Across the Ocean

    Eons

    When Rodents Rafted Across the Ocean

    How did Caviomorpha migrate from South American to Africa?

    When Rodents Rafted Across the Ocean

    Video thumbnail: Eons The Two People We're All Related To

    Eons

    The Two People We're All Related To

    Two humans managed to pass on a very small fraction of their genomes to all of us.

    The Two People We're All Related To

    Video thumbnail: Eons Your Place in the Primate Family Tree

    Eons

    Your Place in the Primate Family Tree

    How did we get from a mouse-sized creature that looked more like a squirrel to you?

    Your Place in the Primate Family Tree

    Video thumbnail: Eons When Giant Amphibians Reigned

    Eons

    When Giant Amphibians Reigned

    A look at when Temnospondyls Amphibians existed for 210 million years

    When Giant Amphibians Reigned

    Video thumbnail: Eons Can We Get DNA From Fossils?

    Eons

    Can We Get DNA From Fossils?

    Scientists have been working for decades to unlock the genetic secrets of the past.

    Can We Get DNA From Fossils?

    Video thumbnail: Eons Did Raptorex Really Exist?

    Eons

    Did Raptorex Really Exist?

    Is LH PV18 a Tarbosaurus bataar? Or a different theropod named Raptorex kriegsteini?

    Did Raptorex Really Exist?

    Video thumbnail: Eons When We First Walked

    Eons

    When We First Walked

    Human ancestors were already walking 3.6 million years ago. But who was first to walk?

    When We First Walked

    Video thumbnail: Eons Life, Sex & Death Among the Dire Wolves

    Eons

    Life, Sex & Death Among the Dire Wolves

    Dire wolves were real! Their remains taught us a lot about how they lived.

    Life, Sex & Death Among the Dire Wolves

    Video thumbnail: Eons The Rise and Fall of the Bone-Crushing Dogs

    Eons

    The Rise and Fall of the Bone-Crushing Dogs

    What happened to the biggest dogs that ever lived?

    The Rise and Fall of the Bone-Crushing Dogs

    Video thumbnail: Eons How a Supervolcano Made the Cenozoic’s Coolest Fossils

    Eons

    How a Supervolcano Made the Cenozoic’s Coolest Fossils

    Yellowstone contains some of North America's most amazing fossil deposits.

    How a Supervolcano Made the Cenozoic’s Coolest Fossils

    Video thumbnail: Eons How Horses Took Over North America (Twice)

    Eons

    How Horses Took Over North America (Twice)

    Horses vanished from North America for 10,000 years until a mammal brought them back.

    How Horses Took Over North America (Twice)

    Video thumbnail: Eons When Birds Had Teeth

    Eons

    When Birds Had Teeth

    How did Archaeopteryx relate to today’s birds? Its teeth provide a major clue.

    When Birds Had Teeth

    Video thumbnail: Eons When Fish Wore Armor

    Eons

    When Fish Wore Armor

    420 million years ago, some fish wore armor – and it may have served a surprising purpose.

    When Fish Wore Armor

    Video thumbnail: Eons The Mystery of the Eocene’s Lethal Lake

    Eons

    The Mystery of the Eocene’s Lethal Lake

    In the 1800s, miners found beautifully preserved fossils of animals from the Eocene.

    The Mystery of the Eocene’s Lethal Lake

    Video thumbnail: Eons When Insects First Flew

    Eons

    When Insects First Flew

    Insects were the first animals to fly. Scientists are still working on how it happened.

    When Insects First Flew

    Video thumbnail: Eons FAQs From Our First Year

    Eons

    FAQs From Our First Year

    To celebrate our first anniversary together, we’d like to answer some of your questions.

    FAQs From Our First Year

    Video thumbnail: Eons How the T-Rex Lost Its Arms

    Eons

    How the T-Rex Lost Its Arms

    Tyrannosaurus rex had tiny arms. How did this happen, and why did it keep them?

    How the T-Rex Lost Its Arms

    Video thumbnail: Eons When Fish First Breathed Air

    Eons

    When Fish First Breathed Air

    Before a group of fish could live on dry land, they acquired the ability to breathe air.

    When Fish First Breathed Air

    Video thumbnail: Eons Where Did Viruses Come From?

    Eons

    Where Did Viruses Come From?

    Where did viruses come from and how did they evolve? Are viruses alive?

    Where Did Viruses Come From?

    Video thumbnail: Eons Why Triassic Animals Were Just the Weirdest

    Eons

    Why Triassic Animals Were Just the Weirdest

    Why the Triassic was full of creatures that look a lot like other, more modern species.

    Why Triassic Animals Were Just the Weirdest