Up Next
Back to Show
Eons
Why We Only Have Ten Toes (It's a Long Story)
Season 4
Episode 22
Today, all mammals from humans to bats have five fingers or fewer. Yes, even whales, whose finger bones are hidden in their fins. Birds have four or fewer and amphibians get the best of both worlds, often having four digits on their “hands” and five on their “feet.” But no species of vertebrates have more than five digits, let alone eight!
Support Provided By
25:37
An extinction in the Middle Permian decimates life, from a fossil reef to our ancient relatives.
25:37
The first herbivorous vertebrates evolve on the side of the amniote family tree leading to mammals.
25:37
Seed plants and amniotes adapt to dry climates, helping them thrive on Pangea in the Permian Period.
9:11
How did Homotherium evolve to be so successful? The answer may lie in the rise of the Tibetan plate.
10:16
The mystery of what non-flying dinosaurs were doing with their feathered wings has a new hypothesis.
11:45
What did ancient people once know about these bizarre megafauna that we’ve since forgotten?
7:44
5,700 years ago, woolly mammoths crossed a remote tundra island off Alaska.
9:48
Why did vertebrates conquer both the land and the air before the depths of the sea?
8:27
Long-extinct dinosaurs may still haunt us—possibly driving us to age faster than any vertebrate.
9:34
Only twice in Earth's history have supermountains risen, and both times reshaped life forever.
10:05
500+ pterosaur fossils found at Solnhofen may be hiding a dark secret distorting our view of them.