This is Bird Note.

For today's Bird Walk, we're going to need our binoculars, some sunscreen, our hiking boots, and this time machine.

Let's set our course for the late Cretaceous Era, 65 million years ago.

Okay, here we are.

As you exit the time machine, please watch your head, mind the gap, and keep an eye out for wildlife.

We've landed on the shore of the Western Interior Seaway, an ocean cutting what will become North America right at half.

Stay alert, there are dinosaurs all around us, of all sizes, and appetites, including some of the earliest birds.

Some look familiar, there are ancient relatives of loons, and ducks, and goals.

And swimming near the shore is a hasperornus, a slim bird about three feet long with stubby wings.

It's flightless and has a long, slender mouth full of sharp teeth.

And what's flying over the water? Diving at fish?

It's an ick theornus, a fully feathered bird, the size and shape of a turn or goal.

At the water's edge is an enantiornithian.

It's the size of a sparrow and looks remarkably like a modern bird, except this bird also has teeth and small claws on its wings.

Well, time to jump back in the time machine.

There's a large asteroid on the way.

That'll be game over for the large dinosaurs, and many of these cool ancient birds.

For bird note, I'm Michael Stein.