From the brains behind brains on, this is the moment of um.

Answering those questions that make you go, um.

Um, um, um, um, um, um, um. Moment of Um comes to you from APM Studios.

I'm Mark Sanchez.

Um.

Okay, it's a sunny day.

The birds are chirping.

The waves are crashing.

And there's just the slightest warm breeze blowing through your hair

scattered all around you are seashells of all different shapes there's spirals sand dollars

sundials ones that whirl around ones that twirl around ones that twist the side, and some that even look like cookies.

Now, stay with me on the beach here and listen to this question that Lily sent to us.

My question is, how do shells get their shape?

My name is Mike Sanchez. I am the Naturalist Center educator at the New Mexico Museum of Natural History and Science.

I consider myself an amateur concoologist. A person who studies seashells, they study the animals that make the shells as well.

Molusks. Those are snails, clams, squid, and octopus. When you see a seashell,

that's an empty thing. That is what's left from an animal that made it. The animal is progressively

getting larger and larger and larger. And as it is, it has to have a bigger and bigger house.

The shell then is its protection.

So the animal is kind of a, like I said, a squishy animal, but it has an organ that is called the mantle.

And the mantle, what it does is it lays out a thin layer of protein that is then acts as the mold that will then make the shape of the shell.

Now in sea water there is also another mineral called calcium carbonate.

...