Tetrapodophis is snek.

It wasn’t necessarily inevitable that fire, or spearpoints, axes, ornament or bows would be discovered when they were. Then, as now, one person could literally change the course of history, with nothing more than an idea.

Sierraceratops, a new horned dinosaur from the Southwest, fits a familiar pattern- different dinosaurs in different parts of the North American continent. Why do we find this?

Snakes originated in the time of the dinosaurs, but fossils of dinosaur-era snakes suggest they were distantly related to living snakes. An evolutionary tree of modern snakes, reconstructed using DNA, suggests that only a handful of species survived the end-Cretaceous mass extinction- and underwent an explosive diversification in the aftermath.

Homo sapiens uses an incredible range of chemicals to alter our minds. When and how did this peculiar habit develop?

Our DNA suggests modern humans evolved around 250,000 years ago, but Homo sapiens fossils known from this time are far from modern. They had big brow ridges, long skulls, and broad jaws like Neanderthals. But while they looked primitive, these people were our contemporaries, not our ancestors. Who were they- and why did we replace them?

At the start of the Jurassic, 200 million years ago, Pangaea starts to break up. By 90 MYA, when duckbills evolved in North America, the breakup was finished- and Africa was isolated from the rest of the world by oceans. By the time duckbills appeared, there was no way for them to get to Africa. Yet they did.

The javelin was a simple but deadly weapon that helped determine the outcome of battles- and therefore shape history- for hundreds of thousands of years. Perhaps no other weapon has played a larger role in our history.

My name is Ozymandias, King of Kings; Look on my Works, ye Mighty, and despair!

A bit of beak- long and skinny, flattened top to bottom, shaped not like a pterosaur, but the beak of a kiwi bird- a bird that uses its long, skinny beak to probe in the dirt for worms.

The Sapiens-Neanderthalensis wars lasted perhaps 100,000 from the time our ancestors first left Africa, until the last Neanderthal was killed.

To war is human- and Neanderthals were very, very human. We’re remarkably similar in the anatomy of our skeletons and skulls, and share 99.7% of our DNA. Behaviorally, Neanderthals were incredibly like us. They made fire, engaged in ritual burial, fashioned jewelry from seashells and animal teeth. They used ochre pigments, possibly for makeup, made art and stone circles. Given that they shared so many of our creative instincts, they probably shared our destructive instincts as well.

When did something like us first appear on the planet? It turns out there’s surprisingly little agreement.

66 million years ago, an asteroid struck the Earth, ending the Cretaceous period. In a moment, the world plunged into darkness, killing the dinosaurs and >90% of all species alive. Today, every living thing descends from the handful of surviving species, but not all survivors thrived.

One theme of my work is systematics: how many species are there, and how are they related to one another?