“A spiked barbarian helmet,” she replied promptly, “And here is Anomalocaris, a huge Cambrian predator, over a foot long.” He paused, but Colene did not laugh; she knew that these creatures were small. “It probably swam in the fashion of a manta ray, undulating through the water, a fearsome sight. Note the vicious feeding appendages, and the circular mouth orifice. It probably acted like a nutcracker, crushing the bodies of its prey.”
Colene was getting into it again. “That’s related to the lobsters?”
“Not at all. It’s no arthropod; it’s in a phylum of its own. Nothing like it exists today. One of the abiding curiosities of the panorama of life shown by the Burgess Shale is that the most successful creatures of that time disappeared without trace, while comparatively minor lines like the chordates survived to prosper. The chordates, of course, were the ones who later gave rise to the fishes, amphibians, reptiles, birds, and mammals. So the mystery is not so much what caused the extinctions—meteor strikes and global changes of weather can account for them—but why certain obscure species survived. I have pondered that often.”
Colene hadn’t thought of it that way. “You mean it wasn’t survival of the fittest? I mean, mammals made it through because they’re better adapted than the reptiles, even the big dinosaurs, being warm-blooded and all. It wasn’t that way back in the Cambrian?”
“It wasn’t that way with the dinosaurs either,” he said. “They may have been warm-bodied too, and there is every indication that they would have carried on to this day if it hadn’t been for a stroke of bad luck. The climate was changing, true, and species of reptiles were declining—but other species were maintaining their vigor. When the meteor came, it was their ill fortune to be large.”
“Huh?” He had caught her by surprise. He was fairly good at that, which she liked.
“We have analyzed it every which way, and the main thing the survivors had in common, through the several extinctions, was their size. They were small. Perhaps they were able to hide in crevices, whether of the land or the sea, until the horror faded. But the big creatures could not hide, so they died. It may indeed be that simple.”
“Gee. Then if there’s another extinction, wiping us out, maybe the roaches will survive to rule the earth.”
“That,” he said seriously, “is no joke. They are even resistant to radiation, and highly adaptable to changing conditions, whether physical or chemical. The roaches are survivors.”
“Let’s look at more pictures,” Colene said wryly.
“Are you trying to distract me from the job at hand?” he asked, with mock severity.
“You don’t think I could actually be interested?”
He shook his head. “I always hope a student will be eager for knowledge. I am usually disappointed. Certainly you are interested in something, but I’m not sure it’s Cambrian fauna.”
Ouch! “Do I get a bonus grade for good work here?”
“Colene, you are already making A’s.”
“Well, I do have a couple of things I want to know. But I don’t know if I want to ask them.”
“Such as whether I really grade classroom legs?”
She paused, astonished. He knew about that story? “That, too,” she agreed.
“Will you promise not to tell?”
She crossed her forearms against her chest in a cute little-girl gesture. “Cross my heart.”
“I do appreciate what is shown, but I don’t grade by it. I never forget that I am a happily married man and that these are adolescents. I am just as glad I’m not teaching at the twelfth-grade level, however.”
He had given her a straight answer! He had admitted that he noticed. “I wish I hadn’t promised,” she said, making a lugubrious face.
“I was glad to see that you are more sensible,” he said. “You are properly dressed, and you are working well. It’s a real pleasure to have a bright student volunteer. If it is information you wish, I shall be happy to answer your questions to the best of my ability.”
There was her opening. But to ask, she would have to reveal her secret concerns, and she wasn’t sure she was ready.
Amos did not push her. That was one of the nice things about him. He was generally willing to live and let live. He displayed another picture. “What does this resemble?”
“A daisy on a Q-Tip?”
“Or a goblet on a thin stem. An inch long, in all. It is Dinomischus, a creature of another bygone phylum. See those two holes in the center of what you think of as the flower? Those are its mouth and anus.”
“Side by side!” she exclaimed, wrinkling her nose. “I’d hate to share its meals.”
“And here is the prize: the strangest creature of all. Hallucigenia.”
“You’re kidding! Nothing’s called that! Scientists are too stodgy.”
“Not always. This has seven pairs of stilt legs, and seven wormlike tentacles on top with tiny pincers. With what may be a bulbous head at one end, and a hollow tail at the other. How do you suppose it foraged?”
Colene squinted at it. “This is a phylum all to itself?”
“Surely so.”
“So there’s no guarantee that it operates any way close to the way we think it should?”
“None.”
“I don’t see how it could walk very well. No joints. It sure wouldn’t move very fast. And what would the tentacles catch, slow-motion?” She pondered. “You know, this thing just doesn’t make a lot of sense to me, as a standalone creature. Could it be maybe part of some other creature, and the head’s not a head but the stump where it broke off?”
“Beautiful!” Amos exclaimed. He put his arm around her shoulders, hugging her. “In one brilliant intuitive flash you have caught up with contemporary conjecture! That’s exactly what has been speculated.”
“Gee,” she said, pleased.
Then he froze, realizing what he had done. He had touched a student! He quickly dropped his arm. “Oh, I’m sorry. I—”
“That’s all right,” she said. “I’ve got a crush on you anyway.” How delightfully similar that was to her fantasy!
“Oh, no! That was why you volunteered to work?”
“That, too,” she agreed, grinning. “May I tell?”
He realized that he had not transgressed. She had merely scored a point. “What, and ruin my reputation?”
She grew bold. “Aw, they wouldn’t believe me anyway. Will you touch me again if I promise not to tell?”
“Absolutely not.”
He was back in Teacher Mode. “Then I guess we’d better get the rest of the work done.”
They resumed the cleanup. But there was now a certain camaraderie between them. Colene had indeed gotten part of what she wanted: closeness and recognition. She found herself humming “To Know Him Is to Love Him.”
“What did you come here for, Colene?” he asked after a moment.
“Will you promise not to tell?”
He imitated her prior gesture, crossing his forearms over his chest. “Cross my sternum.”
“No, I mean really. No private reports, no nothing to nobody. No quiet activity for my own good. You just pretend you never heard it at all.”
He gave her an appraising glance. “It’s that serious?”
“Maybe.”
“I confess you have aroused my curiosity. I undertake to maintain complete confidence.”
That was adult for a promise of silence. He was a teacher, but she decided to trust him, this far. “I have two questions, but maybe they’ll get me in trouble.”
“As I said, I will answer to the best of my ability.”