FOSSILS ET AL.

They Walked the Earth 35 Million Years Earlier Than We Thought

A handful of footprints from ancient Australia is rewriting the story of how life moved onto land

Reconstruction of the early reptile trackmaker alongside color-coded trackways from the Snowy Plains Formation. Front foot (manus) prints are shown in yellow, hind foot (pes) prints in blue. Footprint image: Grzegorz Niedźwiedzki. Reconstruction: Marcin Ambrozik

I still remember crouching over fossil slabs as a master’s student, sweat on my brow and plaster on my jeans, tracing the faint outlines of footprints left behind by long-gone creatures.

Sites like Enciso, in La Rioja, were my playground and my lab. There, in the red beds of the Iberian Peninsula, I first learned how a single toe mark could tell a story that a whole skeleton might miss.

We were always told the Devonian was for fish, the Carboniferous for land animals. The rules felt set in stone. Until now.

A new slab of sandstone from Australia has cracked that timeline wide open.

, small enough for one person to carry, was discovered on the bank of the . At first glance, it might not seem like much. But take a closer look, and you’ll see something remarkable: five slender toes splayed like a fan, and at the tip of each one, a sharp claw mark etched into the stone.

“I was very surprised,” Dr. Grzegorz Niedźwiedzki, “after just a few seconds…