How Blood Evolved (Many Times)9m56s

How Blood Evolved (Many Times)

Blood is one of the most revolutionary features in our evolutionary history. Over hundreds of millions of years, the way in which blood does its job has changed over and over again. As a result, we animals have our familiar red blood. But also blue blood. And purple, and green, and even white.

When Humans Were Prey9m21s

When Humans Were Prey

Not too long ago, our early human ancestors were under constant threat of attack from predators. And it turns out that this difficult chapter in our history may be responsible for the adaptations that allowed us to become so successful.

When Apes Conquered Europe11m45s

When Apes Conquered Europe

Today, our closest evolutionary relatives, the apes, live only in small pockets of Africa and Asia. But back in the Miocene epoch, apes occupied all of Europe. Why aren’t there wild apes in Europe today?

Why Megalodon (Definitely) Went Extinct10m45s

Why Megalodon (Definitely) Went Extinct

For more than 10 million years, Megalodon was at the top of its game as the oceans’ apex predator...until 2.6 million years ago, when it went extinct. So, what happened to the largest shark in history?

The Trouble With Trilobites6m46s

The Trouble With Trilobites

Trilobites are famous not just because they were so beautifully functional, or because they happened to preserve so well. They’re known the world over because they were everywhere!

When Did the First Flower Bloom?4m21s

When Did the First Flower Bloom?

During the Cretaceous Period, dinosaurs were more diverse, more fierce, and more strange than ever. But something else was happening under the feet of the terrible lizards: for the first time in history, there were flowers.

The Tully Monster & Other Problematic Creatures4m01s

The Tully Monster & Other Problematic Creatures

There are animals in the fossil record that challenge some of our most basic ideas about what animals are supposed to look like. If there ever was a monster on this planet that was worthy of the name, it might have been the Tully Monster.

How Sex Became A Thing5m39s

How Sex Became A Thing

We don’t know which living thing was the very first to arrive at the totally revolutionary process that is sexual reproduction but we can follow the history of how (and why) sex became a thing.

The Other Explosion You Should Know About6m25s

The Other Explosion You Should Know About

Fossils found around the world suggest that multi-cellular life was not only present before the Cambrian Explosion, it was much more elaborate and diverse than anyone thought. This is the story of the sudden burst of diversity that marked the dawn of truly complex life on our planet.

How the Turtle Got Its Shell8m29s

How the Turtle Got Its Shell

Where did turtles come from? And how did the they get their shells? The answers to these questions would eventually cause scientists to rethink the entire history of reptile evolution.

What a Dinosaur Looks Like Under a Microscope8m09s

What a Dinosaur Looks Like Under a Microscope

We traveled to Bozeman, Montana to meet with Dr. Ellen-Thérèse Lamm who explores ancient life by studying it at the cellular level. Kallie and Dr. Lamm discuss how she does this, and what she’s learned by putting dinosaur bones under a microscope.

The Most Useful Fossils In The World5m49s

The Most Useful Fossils In The World

For decades, one of the most abundant kinds of fossils on Earth, numbering in the millions of specimens, was a mystery to paleontologists. But geologists discovered that these mysterious fossils could basically be used to tell time in the deep past.

When Birds Had Teeth11m29s

When Birds Had Teeth

Experts are still arguing over whether Archaeopteryx was a true bird, or a paravian dinosaur, or some other kind of dino. But regardless of what side you’re on, how did this fascinating, bird-like animal relate to today’s birds? It turns out its teeth were a clue that this story goes all the way back to what we now call the non-avian dinosaurs.

How Horses Took Over North America (Twice)9m08s

How Horses Took Over North America (Twice)

The ancestors of modern horses became so successful that they spread all over the world, to Europe, Asia, South America, and Africa. But in their native range of North America, they’ll vanish for 10,000 years. Until another strange mammal brings them back.

The Rise and Fall of the Bone-Crushing Dogs8m29s

The Rise and Fall of the Bone-Crushing Dogs

A huge and diverse subfamily of dogs, the bone-crushers patrolled North America for more than thirty million years, before they disappeared in the not-too-distant past. So what happened to the biggest dogs that ever lived?

The Story of Saberteeth5m26s

The Story of Saberteeth

Smilodon was a fearsome Ice Age cat, the size of a modern-day tiger, that had a pair of fangs nearly 18 centimeters long. But it was only the last and largest of the great sabertooths: ridiculously long canines had already been a trend for millions of years by the time Smilodon was prowling around. And you know what? Those giant teeth just might make a comeback.

That Time Oxygen Almost Killed Everything4m45s

That Time Oxygen Almost Killed Everything

What if we told you that there was a time when oxygen almost wiped out all life on Earth? 3 billion years ago, when the world was a place you’d never recognize, too much of a good thing almost ruined everything for everybody.

The Biggest Thing That Ever Flew4m48s

The Biggest Thing That Ever Flew

Today, we’re familiar with two types of flying vertebrates -- birds and bats. But over 66 million years ago, there was a giraffe-sized reptile that soared through the sky.

Dimetrodon: Our Most Unlikely Ancestor5m21s

Dimetrodon: Our Most Unlikely Ancestor

With its lizard-like appearance and that distinctive sail on it back, Dimetrodon is practically the mascot of the Palaeozoic Era, a time before flowers, birds, mammals, and even crocodiles. But if you take a close look at this sail-backed animal, you might see a little bit of yourself.

The Extinction That Never Happened7m36s

The Extinction That Never Happened

Natural history is full of living things that were long thought to have gone extinct only to show up again, alive and well. Paleontologists have a word for these kinds of organisms: They call them Lazarus taxa.

The Strange Case of the Buzzsaw Jaws3m54s

The Strange Case of the Buzzsaw Jaws

There are many fossils that challenge our ability to form even the most basic idea of how a living thing looked, or lived, or functioned. One of the longest-running of these mysteries involved a 270-million-year-old sea creature called Helicoprion that once swam the seas around the supercontinent of Pangea.

The Age of Giant Insects5m28s

The Age of Giant Insects

Insects outnumber humans by a lot and we only like to think we're in charge because we're bigger than they are. But insects and other arthropods weren’t always so small. About 315 million years ago during the Carboniferous Period, they were not only abundant: they were enormous.