Convergent evolution

You were describing, you were like going through it so well.

So the move out into the water, episode 231, has happened many times, episode 70, Convergent Evolution,

like in

Dolphins, episode 41, and Sea Turtles, episode 244.

Now, the hadrosaurs...

Convergently with the ceratopsids evolved these batteries of teeth.

So it's not ancestral, it's convergent with ceratopsids, but they did the same thing where they could chew their food.

So unlike sauropods and unlike other, like stegosaurs and other ornithischians, they were able to bite the food with their beaks and chew it.

Like, sometimes a behavior and adaptation is just so amazing that early zoologists decreed it couldn't have possibly evolved more than once, so that all animals with that trait must be related.

But as we've seen several times in this course, convergent evolution happens all the time, even for fairly complex traits.

One example is termites, which are eusocial and live in mounds with a reproductive queen and non-reproductive soldiers, workers, and other highly specialized roles.

For a long time, they were grouped alongside ants and bees in the order Hymenoptera, because eusociality requires so many coordinated changes in an animal's body and behavior that early zoologists figured it probably only evolved once.