Credit: Image: iStockphoto

Trey continued to poke and pry at the dead thing, but evidently he saw the look I was giving the boy.

"If it's a prank," he said, "it's a damn clever one. Too clever to have been cobbled up by a kid. You don't just doctor up a bunch of shrimp or crabs and pass 'em off as trilobites."

The boy swelled with triumph and defiance.

"Trey," I said, "have these things possibly been down there all this time, at the bottom of the bay?"

He shook his head helplessly. "No. Of course not. They have to have come from somewhere else."

"From way deep in the Gulf of Mexico, you think?"

"I don't know what to think right now."

"But isn't it possible..."

"I don't know. Until this very moment there's never been the slightest reason not to believe that trilobites died out completely in Palaeozoic time. Their closest living relatives are horseshoe crabs, and there's no mistaking the one for the other. But there's no mistaking these, either. Di, did you bring your phone?"

"No. Sorry."

"Eric, I need to call the museum from the condo."

I handed over my keys.

"Stay right here," he said, "keep the birds away, don't let anybody move any of these things," and he jogged away heavily.

The boy positioned himself possessively between us and the greater part of the stranded arthropods. "I found them," he said, "they're mine."

"Looks like there are plenty here for everybody," Dianne said. "Surely, you can spare us a few."

He looked around as though computing just how many he might be able to spare us.

"My husband's a scientist. He wants to study them."

The boy did not seem too impressed. "Are they worth a lot?"

"No," I put in flatly. "Not in the way you're thinking. But if you help us keep the birds off so he can collect some for his museum, he might end up naming them after you."

Interest flickered in his face. "He can do that?"

"Yes. And once a scientist officially names something, nobody can name it anything else."

"First I wanna show my mum and dad." He nodded toward a couple who were approaching at a purposeful pace, then ran off toward them.

"Thanks for deflecting the money question," Dianne said.

"I deal with tougher questions from kids his age all the time."

Some distance away, the boy and his parents drew up in a knot, and there ensued much gesticulating on the boy's part and some sharp looks in our direction on theirs. I asked Dianne out of the corner of my mouth, "Can we actually not let anybody move any of these things? It's a public beach."

The kid and his parents drew near, and he looked around and said, "Where's the other man who's gonna name these things after me?"

Dianne essayed a smile that would have disarmed me in a hot second but somehow glanced right off the kid's parents. "He means my husband," she said, gesturing vaguely. "He's a marine biologist at the marine museum in Corpus."

The man ran his tongue around the corner of his mouth as he considered the dead arthropod. "What is this thing?"

The boy piped up precociously, "The man said it was a prehistoric trilobite!"

"It does appear," I said to his father, "to be a type of animal supposed to have become extinct hundreds of millions of years ago. Even before the dinosaurs."

The man regarded me with a mixture of incredulity and disdain, and looked as though he meant to challenge my remark, but then his wife, evidently a veteran observer of past encounters, made an abrupt show of consulting her watch and broke in chirpily with, "Dear, I just remembered, we have that thing to go to this afternoon."

The man exhaled harshly. "What thing is that, honey?" he asked, not taking his eyes off me.

She didn't explain what thing it was but instead said to me, "I'm sorry, I'm such a ditz for forgetting, but we've really got to get moving if we expect to be ready in time."

As they moved off, I asked Dianne, "Should I have handled that better- whatever it was?"

"I won't even venture to guess what it was."

Trey returned. "Carl and Bart are on the way. Bart knows this stuff better than I do." He grimaced at his wife. "He says I am, and I quote, nuts. Well, it is nuts. Trilobites."

"Maybe," I said, "they really are from someplace else. From some time else, I mean. As in time travel. The fabric of space-time tore open and let these things through."

"Eric, Eric, give me a break, Eric. Please."

"Well, right now, it's as likely as anything else."

"No, it's about as unlikely as anything else." He glared at me in exasperation. "Even when we were kids, you always were into some weird damn thing or other."

"We both were."

"No. I was into science. Prosaic, down-to-earth science. You were into weird science – romantic science-fiction."

"Well, if this isn't a weird science-fiction thing..."

"Well, it is weird, but whatever it is, it's science, Eric. Some way or another, there is a logical, scientific explanation."

"I know from logical, scientific explanations," I told him, more heatedly than I probably intended. "After all, I am..."

"Guys," Dianne said evenly.

Trey and I looked at her and at each other, and both of us were abashed.

"Still," I said in a calmer tone, "the obvious logical, scientific explanation is there's a lost colony of trilobites at the bottom of the Gulf of Mexico. Why not? The coelacanth was swimming around off Madagascar all that time before anybody knew it was there."

"Yes, and stromatolites have survived in Australia, and Lingula is still around, too. And they're both a lot older than the coelacanth. But people have fished and shrimped in these waters for generations without hauling up even a single trilobite. Never mind a mess of the things."

"Which brings us right back to the only other logical scientific explanation I can think of. These trilobites were hurled out of their own time, into ours, and the shock killed them."

"Ah, God, Eric! I am not going to stand here arguing about time warps with somebody who used to pretend that Granddad's cows were dinosaurs."

"Hey! You pretended right along with me."

Dianne cocked an eyebrow, probably at both of us. Trey shrugged embarrassedly, and I said, "Until you come up with a better explanation, this is lost-world stuff or time-warp stuff." He turned his back on me. "Trilobites fresh enough to use as fish bait, Trey."

Looking out over the bay with his fists on his hips, Trey said, almost wistfully, "There's just not much room left anywhere on earth for macro survivors from prehistoric times. No lost worlds, no dinosaurs hanging on in Darkest Africa or the Amazon jungle. Darkest Africa's been fully illuminated."

Dianne nodded. "Fully and sometimes horrifyingly."

"Yeah. And the Amazon jungle's been turned into grazing land for cattle. And even the sea bottoms are no haven. They're home to some extraordinary life forms, but there's no part of the ocean floor that's older than one hundred million years. There's no stable marine environment where trilobites could have hung on since the Paeleozoic."

He did not sound entirely convinced now.