Sooz sighed and threw down her pencil. “Coprolite!” she said. “This is just one big piece of coprolite.”

(In second grade, I made the mistake of telling Sooz the scientific term for petrified dung.)

“Coprolite, coprolite, coprolite!” She crumpled up her paper. “I suck. I have coprolite for brains. You do it.” She threw the paper at me.

“No way. Uh-uh.” I was a decent artist—you have to be, if you want to be a paleontologist, all of those bones and fossils to sketch while on a dig—but I was mechanical. I could draw something right in front of me, but I couldn’t invent. I couldn’t draw the pictures in my brain, the way Sooz could.

I looked at the piece she’d thrown at me. It was gorgeous. Just not up to Sooz’s impossible standards.

She sighed again. “Who knew high school would be this hard?”

“What? It’s not hard. We’re both doing…”

“I mean guys,” she said. “Jamie.” She looked at me. “You know—dinosaurs.”

The next day, sitting at lunch, Sooz read A Song Flung Up to Heaven. I read Scientific American. That was how we rolled.

“Apatosaur in the house,” Sooz murmured.

I followed her gaze. Andi had sashayed into the lunchroom. Jamie followed, carrying two lunch trays. He always did that for her. I loved the way he balanced both trays so carefully, but casually, like it was nothing. His arms went all taut and on days when he wore short sleeves (like that day), I could see the tension in his biceps and their hardness.

He had a tattoo of a flaming baseball on his left arm, just below the cuff of his T-shirt. I saw it all the time in biology because he sat to my right and I looked at it all the time and it was like it was tattooed on my brain.

My bio notebook was filled with pages of me drawing that tattoo over and over again, applying my meager art skills to it as if it were a thigh bone from a brachiosaur found on a dig, and I was trying to capture it, pristine and perfect, before plastering it and shipping it off to a museum.

In the meantime, my sketches would be all the world would see.

Drawing that baseball, over and over…

“Apatosaur,” Sooz murmured. “Apatosaur.”

Her nickname for Andi. Apatosaurs had a terrible brain-to-body-mass ratio.

Jamie put Andi’s tray down in front of her. Nothing on it moved at all. He sat down across from her after accepting a quick kiss on the lips that was gone before a teacher could say anything.

“Ugh,” Sooz said. “Don’t you just hate her?”

“No. I just want to be her.”

And it was true. If I could be Andi, I would be the world’s greatest Andi. I adored Andi—her hair, her body, her walk. Her clothes. She wore clothes effortlessly, like she just woke up every morning and her clothes flowed onto her body. The right colors, the right fit, the right style. I loved everything about her. She was perfect.

And, of course, she had Jamie.

Sometimes I imagined that she and Jamie weren’t going out anymore. And Jamie and I started dating, and Andi was cool with it and we were all three great friends. Sometimes I imagined that she had never dated Jamie, that she was just this perfect girl without a boyfriend, and even though I had Jamie as my boyfriend, I was still friends with her, still nice to her, and I was never jealous if Jamie wanted to hang out with her alone because I trusted both of them.

“You need to get him out of your system,” Sooz went on, snapping me out of my fantasy world. “It’s weird. As long as we’ve been friends, you’ve always been single-minded. Dinosaurs, dinosaurs, dinosaurs, from Day One. Now you have this new obsession and I don’t know how to deal with it. Get back to your lizards.”

“They’re not lizards. They’re both from subclass Diapsida, but dinosaurs are archosaurs, while lizards are lepidosaurs. Two different things.”

Sooz grinned. “I love when you do stuff like that. I have no idea if you’re making it up or not, but it sure sounds good.”

Of course, I wasn’t making it up. None of it.

In kindergarten, when they asked what we wanted to be when we grew up, I said paleontologist. (Actually, I said, “plentyologist” because I couldn’t quite wrap my mouth around it yet…but I could spell it.) By first grade, I had the pronunciation down pat. Enough so that a boy once accosted me on the playground while I was sitting off to one side, reading a dinosaur book. “You’re not really a girl,” he said. “Girls don’t like dinosaurs.”

I blinked. “What do you mean? Of course I’m a girl. I’m wearing pink.” I pointed to my headband, just in case he didn’t get it.

Third grade: A-plus for my paper on theropods. Eighth grade—just last year—won the science fair with my project showing the difference between ornithischian and saurischian hips. I built my models painstakingly over a month, using books and Web sites for reference. I made Mom drive me to the museum in Washington DC two weekends in a row so that I could talk to one of the paleontologists there. Dr. Marbury liked me and let me e-mail him pictures of the project in progress. I wouldn’t let him help me, though. I had to do it on my own.

Dr. Marbury was so impressed with me that he said that—if my parents approved—he would take me on a dig with him. He had one scheduled for the summer of my junior year. I thought my eyes would pop right out of my skull. (Fortunately, that’s biologically unlikely. It does happen, though.)

That was a year ago and I still stayed in touch with him and he still wanted to take me and, honestly, nothing else mattered. I didn’t care that the other girls were getting into makeup and boys. I didn’t care that I only had one friend. I didn’t care that I wasn’t glamorous or that I was what Mom called a “late bloomer.” I didn’t care that boys didn’t think I was a girl. I didn’t care about any of it. I saved my money and I didn’t waste it on clothes or makeup or music from bands with hot guys in them or anything like that. Digs are expensive. I would need equipment. I would need stuff.

I didn’t care what it cost or what I had to sacrifice to get there. I just wanted to go on a dig. I wanted to be there, to find the remains, to brush away the dirt and the sand, to gently pry from the earth the bones of its past.

To sketch them and make them immortal.

The Field Museum of Natural History in Chicago has one of the most complete T. rexes in existence, nicknamed Sue after the woman who found it. I just wanted a dinosaur nicknamed Katie—or even Katya.

That was all I wanted.

Until high school started.

Until Jamie.

Suddenly, I wanted something else. And I had no idea how to get it.

At her table, Andi got bored with food, apparently. She stood up and bounced a hacky sack from knee to knee, occasionally flipping up a foot to kick it up even higher. Everyone at her table watched and applauded. Even Jamie.

I am uncoordinated. If there is a piece of furniture in the room, trust me to stub my toe on it. I’m sort of like an allosaur or a T. rex—they could move somewhat quickly, but only straight ahead. The saurischian hip structure isn’t designed to swerve from side to side, so they blundered in a straight line, sometimes changing direction by shifting their weight with their tails. But dodging? Sidestepping something? No way. Can’t happen. It’s just a fact of anatomy.

“Close your mouth,” Sooz whispered to me. “You’re chewing like a theropod.” She picked up some of the lingo just from hanging out with me. Theropods were meat-eaters.

The lingo, but not the facts.

“Theropods didn’t chew their food,” I told her. “They didn’t have crushing teeth like we do. Their teeth were for tearing. Like this.” I demonstrated with my hamburger, attacking it with my front teeth, tearing off wads of meat and bread and growling.

Sooz looked at me in horror.

“See?” I told her, after I’d gotten it down. Grease and ketchup dripped down my chin. I wiped at it with a napkin. “They would just tear off chunks and then swallow them whole.”

“Um, Katya, you’re really loud….”

“They had these awesome teeth with serrated edges, called denticles?—”

“Katya…”

“Testicles?” someone said much too loudly.

I looked over my shoulder. At the table behind us, everyone was laughing, mimicking the way I’d chomped my burger.

“She said they have testicles for teeth!” one of them howled.

“No, not testicles. Denticles. They were for?—”

“Katya.”

“What?” I turned back to her.

“Let it go.”

I checked over my shoulder again. “I’m eating with my testicles!” one guy said in a mockingly nerdy voice, holding a French fry near his crotch.

“What am I going to do with you, Katya?” Sooz asked, and shook her head.

Only Sooz ever called me Katya. My real name is Katherine and everyone called me Katie, but Sooz said Katya was more exotic and claimed she would call me Katya for the rest of my life, even during the maid of honor’s toast at my wedding.

“I’ll never get married,” I told her. “Guys don’t like geeks.”

“You know,” Sooz said as we left the cafeteria, “it’s okay to do the dinosaur stuff with me. I like it, even when I don’t get it. But not everyone’s like that.”

“But dinosaurs are important! They ruled the earth for millions of years. When we study them, we can understand not just them, but also the way the world was, the way the world changed, maybe even what the world is changing into.”

She gave me the special Sooz look, the one that meant I was talking too loud again. Sure enough, people around us were snickering, shaking their heads, rolling their eyes. A few junior boys tucked their arms up like velociraptors and staggered around like drunk birds.

“Any day,” I said, more quietly, “we could wake up and there could be a discovery that could change everything. Right now, while we’re standing here, there are bones, Sooz. Bones and other fossils, filed away in museums all over the world. They’ve been in the ground for millions of years and they’ve been sitting in the basement of some museum for ten years or more, but every single day, someone looks at one of them for the first time. And that could be the one that changes everything. We could hear about it on the news any moment. Isn’t that amazing?”