Summary

Learn about the deep evolutionary origin of birds and follow their history up to the great extinction that happened 66 million years ago.

First, I discuss what we mean when we say “bird.” What characteristics separate modern birds from other animal groups?

Then I discuss the evidence—both historical and recent—that scientists have used to determine the evolutionary history of birds. 

Finally, we arrive at the answer of where birds fit on the tree of life.

Research Citations

• Discovery of collagen protein in Tyrannosaurus femur (Asara et al. 2007. Science)‍
• Archaeornithura, the earliest known true ancestor of birds (Wang et al. 2015. Nature Communications)

Errors and Clarifications

Error - 05:39 min: I say that scientists have genome sequences for 'all living birds.' What I meant was that we have genome sequences for representative species within each of the living bird families.