Welcome to a new segment here on Dino News

that we're calling "Microscope on the Mammals."

MAZU: It's true that dinosaurs dominated the Cretaceous Period,

which lasted millions of years.

ROCKY: Dinos rule!

MAZU: But another group of animals also began to flourish:

the mammals.

Want to tell everyone what a mammal is, Tiny?

TINY: Sure! A mammal is a warm-blooded animal

that has a backbone, breathes air, grows fur or hair,

and drinks its mom's milk when it's a baby.

BILL: The only milk I drank as a baby was coconut milk.

And still do! Yum!

MAZU: Most mammals during the Cretaceous Period

were small, scurrying mouse-like creatures.

- ROCKY: You mean, like Rugo? - MAZU: That's right.

These little mammals came out mostly at night.

ROCKY: Not our Rugo!

BILL: Yeah, I would call her a "morning mammal."

TINY: And that energy continues right through the day!

MAZU: You can say that again!

Anyway, experts also think

these little mammals ate small stuff,

like leaves and insects.

ROCKY: But not our Rugo!

TINY: Yeah, she'll eat anything, no matter how big!

ROCKY: Including Giganto's lunch!

BILL: You know,

she might be the only one

in Cretacia who eats more than me.

MAZU: You might be right, Bill.

The last theory we'll discuss today

is that these mammals stayed small

to hide from big dinosaurs.

ROCKY: Are you kidding? That's definitely not our Rugo!

TINY: I'll say! She sure loves Giganto!

BILL: And he seems pretty fond of her, too!

MAZU: It's true, Rugo sure is special in many ways.

We're lucky to have her as a friend.

ROCKY: Yep.

Any friend of Giganto's is a friend of mine!