Eocene · about 50 million years ago
The whale that still had legs.
Pakicetus waded the shores of an ancient sea on four feet. Keep scrolling and the page walks it backward, one ancestor at a time, until the land runs out.
Paleocene · about 60 million years ago
Already not a whale.
A small hoofed mammal at the water's edge. The ear bones that will one day hear underwater are still ordinary.
Closest living relative of whales: the hippopotamus.
Jurassic · about 165 million years ago
A world of giants, seen from a branch.
Every mammal alive today, whale included, descends from something about this size that kept out of the way of dinosaurs.
Permian · about 280 million years ago
Not a dinosaur. Your relative.
Dimetrodon is a synapsid, the branch that leads to mammals. It was gone tens of millions of years before the first dinosaur appeared.
The number in the corner just passed 300. The thing on screen is still an ancestor.
Late Devonian · about 365 million years ago
Limbs that barely work on land.
Ichthyostega had seven toes on each hind foot and a fish's tail. Walking was still an experiment.
Devonian · about 375 million years ago
Back in the water.
This is where the whale's story starts: a lobe-finned fish testing the mud. Every lineage on the channel ends at a place like this.
Watch the lineages