He moved a few paces to the gastropod display. Here there was much greater variety, for the shells were coiled, ridged and spired diversely, and several were very pretty. But these too were not definitive for his purpose.
It was, in fact, mainly what was missing that fascinated him. There were very few cephalopods. He had search diligently and come up with only two shells, both belemnites.
That was highly significant, for the cephalopods had dominated the seas of Earth for three hundred million years before suffering certain, selective but drastic extinctions. The belemnites had given way to their squidlike cousins - but the geological period in which belemnites had existed in the absence of ammonites was restricted.
The picture described by his carefully ordered collection of shells was remarkable. He was not properly versed, without his reference texts, in every detail of invertebrate fossilography; but he was certain that coincidence did not stretch this far. The fauna of the shallows here matched those of Earth, order for order, and probably species for species. Not contemporary Earth, no. Not truly ancient Earth, either. But definitely Earth.
In fact, the evidence of the sea shells reinforced that of Aquilon's map in exactly the way he had incredulously anticipated. He had recognized its configuration without daring to believe it, and suppressed his burgeoning excitement. The Earth authorities, unused to paleogeographical perspective, had apparently missed its significance. Now he looked at shells that suggested either a preposterous coincidence of convergent evolution, or -
Or they stood upon an island in the oceans of an Earth of sixty-five million years past. No - not an Earth -
The Earth.
Aquilon walked up the beach, resplendent in a one-piece bathing suit. It covered more of her flesh than certain contemporary fashions would have, on or off the beach; but she was perfect In it. Her hair in the sun was almost white, in contrast with the black of the suit, while her skin already showed an enhancing tan.
'Have to come in before I burn,' she said, joining him in the shade of the display tent. 'And I'd better catch up on illustration, too.' She brought out her brush - somehow she was never without it - and began sketching the shells of the display.
Should he tell her what he had discovered? No - not right away. It would only disturb her unnecessarily. Time travel, after all...
'This is Earth, isn't it,' she said calmly as she sketched.
'Yes.' So much for feminine histrionics. Would he ever fully understand this woman? 'How did you know?'
'Your silence, mostly. You should have been exclaiming over divergencies, and parallels, since this is by any reckoning a sharply Earthlike world. If it were a true parallel, it would be contemporary, and even I can tell it isn't. And you knew something when you had me sketch the map - yet you never spoke of it again. When I thought about it, I realized that there was a certain familiarity about that map, as though were a gross distortion of the geography we have today. Earth might once have looked like that, millions of years ago - and you would be the first to spot it. But you shut up - and you're wound up like one of these shells.'
Had he shown his tension so obviously? 'You've been apprenticed to an agent, I suspect.'
She did not reply. Low blow, he realized then. The age; Subble had made an impression on her, how much of one was only gradually coming to appreciate. Best to move off the topic. 'Does Veg know?' he inquired.
'Maybe. It doesn't matter much to him, though. When this - the Permian?'
'Off by two hundred million years, 'Quilon. It's, the Paleocene.'
'The Paleocene,' she mused, placing it. 'Dawn of the age of mammals, if my girlhood schooling does not betray my aging memory. Vice versa, I mean. I think we should have be... safer in the Permian, though.'
'Oh, there are few dangerous landbound forms in this epoch. With the reptiles decimated-'
'Safer from paradox, I meant.'
There was that. Could their actions here affect the evolution of man. It seemed incredible, yet -
'What are these?' she inquired, her brush moving and rendering as of its own volition. Shape, shade, and color were artistically duplicated, the pigments flowing from the brush in response to subtle signals from her fingers, without dipping, without rinsing.
It was an abrupt change of subject, but he accepted the shift with relief. 'Phylum Mollusca - or as Veg would say, shellfish.'
'You underestimate him, difficult as that is to do at times. He calls them clams and conks.'
'He's right. The hinged shells are pelecypods, commonly known as clams. Most of the others are gastropods - Greek gaster, meaning stomach, and pom, foot. This army really does march on its stomach -'
'Like the mania,' she said.
Cal paused, surprised. 'Yes indeed. Strange that that similarity hadn't occurred to me.'
'But the mantas don't carry their houses on their backs.' She turned over a gastropod shell in order to get a new view for sketching. 'I studied tetrapodal anatomy, but I'm beginning to wish I'd learned more about sea life. These shells are 'beautiful.'
'Anything you paint is beautiful.'
She ignored that. 'What do the live animals look like?'
'Like snails. That's what they are. As they grow larger, they add on to their domiciles, forming the spirals you see. Because the result is really a horn - an expanding tube - it is possible to sound a note on the empty shell, when it is properly prepared. Thus Veg's conch, or "conk". He'd have trouble sounding a blast on an ammonite, though.'
'Which of these are ammonites?'
'None. They're extinct. That's one reason I know this is the Paleocene and not the Cretaceous period.'
'How can you be sure? Maybe you just didn't happen to scoop up any ammonites.' She was teasing him, anticipating his reply.
He made it anyway, enjoying her smile. Any dialogue with Aquilon was pleasant. 'My dear, you are asking for a tedious narration of marine paleontology -'
'Oops - not that!' She continued painting.
'The major distinction between the shells of the gastropods and those of the cephalopods is compartmentalization. The ail shells are hollow throughout, forming a single valve; but those of the cephalopods -'
'You forgot to tell me what cephalopods are,' she said. 'What do they look like, in life?'
'Squids in shells. Your snails and clams are sluggish in the mature state, but the cephalopods are active. They have keen eyesight and are strong swimmers, despite their hardware. They have a number of tentacles around the mouth. The halopods as a class have been abundant and important in the seas for well over three hundred million years, and are the only invertebrates able to compete actively with the ocean vertebrates. The giant squid -'
'But you were talking about shellfish, not squids!'
'Mollusca. Some wear their shells outside, some inside. The squid's shell is vestigial and internal, so you're not aware of it. The ammonite shell is external and, as I was about to explain, chambered. Segments of the ulterior are walled off as the creature grows, and these are filled with gas to make the dead weight more manageable. A sophisticated, highly successful format - and the ammonites were virtual rulers of the sea for a length of time that makes the tenure of the great reptiles of land seem brief. Yet the ammonites suffered a series of calamitous decimations, marking off the Triassic, Jurassic, and Cretaceous periods, and finally became extinct just before this Paleocene epoch. Their passing is, to my mind, a more subtle and significant mystery than that of the complex of reptilia orders that claims popular attention. In fact, the ammonite passed at about the same time as the dinosaurs.'
'The same time,' Aquilon repeated, seeming to appreciate the significance of that. 'But some reptiles did survive, and some mollusks.' She had finished her painting.
'A few reptiles like the lizards, snakes, and crocodiles, turtles. But none of the ammonites, only the related but primitive Nautiloids. They have the septa in the shell - simple saucer-shaped partitions - but with comparatively unimaginative convolution. The ammonites
in their time developed extraordinary elaborate fluting, and with much greater variety.'
'We shouldn't stay here,' she said, evidently tired of ontology at last, 'on the island.'
'I've hardly begun to catalog -
'Circe says something is happening.' He studied her, realizing that she was seriously cone and had only listened to him in order to have time to settle own thoughts. Circe was her manta, just as Hex was Veg's, news from that source had to be taken seriously.
'Can you be more specific?'
'We don't have the terms, the words. But it's something. She doesn't know whether it's dangerous, but it might something about the water.'
'Storm?'
'I don't think so. And we'd know about that ourselves, wouldn't we?'
'We should. We have a fair selection of meteorological instruments. The barometer doesn't indicate trouble, and we'd have some advance warning if a hurricane were coming. Enough to retreat to the undersea tube, I'd think. Could the water be polluted in some way?'
'We'd know about that too, wouldn't we? What would pollute it, here?'
He shrugged. 'What indeed, without man's machine age. Perhaps I should question Circe directly.'
He could tell by her attitude that this was exactly what she'd had in mind. Aquilon put two fingers to her mouth and delivered a piercing whistle, astonishing him. In a moment the disk shape of a traveling manta rounded the curve of the island, moving at a good thirty miles per hour over the water. Circe.
'What's this I hear about the water?' Cal inquired as the creature came to rest before him.
Circe did not move or snap her tail, but Aquilon responded. 'She doesn't know what you mean, Cal.'
'There is something wrong with the water,' he said, making a statement.
Now Circe snapped her tail twice: no.
'Something will be wrong.'
Three snaps: question.
'The water will change.'
Yes.
'Warmer.'
No.
'Colder.'
No.
'Higher.'
Yes.
Suddenly it clicked. 'A wave!'
Yes.
Tsunami!'
Question.
'A big wave caused by movements of the land. Very big.'
Yes.
'How soon? One day?'
No.
'Sooner?'
Yes.
'Twelve hours?'
No.
'How many hours?'
Six snaps of the tail.
Cal stood up. 'Get Veg. We have to get off this island in a hurry. We have just about time to batten down before it hits.'
Circe was up and away, though he had been addressing Aquilon. That was just as well; the manta could spread the news more efficiently.
But Veg, when notified, threw an unexpected block. 'No. I'd rather ride it out right here. I don't want to go back in the can.'
'It would only be for a day or so,' Cal explained, but privately he shared the big man's reluctance. They joked about Veg's obtuseness, but he generally knew what was going on. And by this time the spore problem at the orbiting station would be in full swing, and the personnel could be in a very bad mood. 'Until the danger is over. Then we can resume work here.'
'Well, I've been thinking,' Veg said. 'Out here in the sun and spray, no problems, no people crowding together, not even rationed cutting rights. I like it. It's the way a man is meant to live. Down there - we'd be walking back into the tin can, squeezed tight. That's what the trouble is back on Earth. Crowded. Here it's good; there it's bad. I don't want to go back. At all. Not even for a day.'
Oh-oh. When Veg thought something out, he could be obstinate, and the irony was that Cal agreed almost entirely. It was possible that they would be in greater danger in the tunnel than on the island, though from a different source. But at least they could remain near the borer exit. 'Let me explain what a tsunami is,' he said carefully. This was for Aquilon's benefit too, to be certain everyone knew what the choices were. 'An Earthquake or erupting volcano can do enormous damage on land, but if it is in or near the sea it acts in a different way. It makes a wave - a shift in the level of the water, a number of inches or feet. This wave travels at a rate governed by the amount of the disturbance and the depth of the water; it is a top-to-bottom matter, not just a surface ripple like those the wind makes. In deep water its forward velocity can exceed six hundred miles per hour. Because the vertical displacement is proportionately small, ships at sea may not even be aware of the tsunami's passage - but once it strikes the shallows, its full impact is felt. Forward momentum is converted to vertical
displacement. The water can rise up in a wall a hundred feet high, and demolish shore installations with its impact.
'Now we don't know how bad this one is - but this is a small island without any really high land. A large wave could inundate it completely. Back on Earth such waves used to kill thousands and carry ships miles inland. Here -'
'Only three people, and four mantas,' Aquilon said. 'Hardly worth its while.'
Veg retained that determined expression. 'You said ships could ride it out.'
'Ships in deep water, yes. Not those too near the shore.'
'How about a raft?'
'A raft!' Aquilon repeated, becoming interested.
'The matter is academic,' Cal pointed out. 'We don't have a raft - unless you're thinking of the emergency balloon-type craft. I wouldn't care to risk it. One puncture -'
'How about a log raft? Good solid timbers, rudder, cabin, sail -'
So that was what Veg had been doing! Trust an outdoors-man to put his talent to work. 'All right, Veg. Let's see it.'
The raft floated in a cove on the far side of the island, about twelve feet wide and twenty feet long, fashioned of stout, round palm logs bound together by nylon cord set into notches. In the center was a cabin six feet square, and from the center of that rose a ten-foot mast of sturdy bamboo.
'Haven't made the sail yet,' Veg admitted. 'But she has a six-foot keel and the cabin's tight. I call her the Nacre.'
'And you hope to ride out a tsunami in this?' Cal shook his head, though he was impressed with his friend's accomplishment.
'Why not? You said ships wouldn't even notice the wave. Nacre's unsinkable. And we have to look about this world sometime.'
'It seems reasonable to me,' Aquilon said.
Cal tried to marshal his objections, but saw that he had already been outvoted. Or was he compensating for his own unreasonable desire to get far away from the works of Earth-contemporary? Or could he actually want to reach some area of this world where their actions might prejudice the development of the primates, and therefore abolish man from the globe entirely? No, the paradox inherent made that notion ridiculous. 'I hope there is a survivor to tell the tale,' he said morosely.
It required four hours of strenuous group labor to load their supplies and tie everything down. Cal had to agree that it would not have been feasible to convey everything to the undersea tunnel in that period. They would have had to sustain a serious loss of supplies, unless the wave were minor. But Circe could probably not have detected the advance tremors of a minor one. Perhaps this raft, fragile as it seemed, was the best alternative. But with only two hours to reach deep water, and no sail -
They boarded and pushed off without ceremony. Veg poled the craft out from the island while Cal and Aquilon paddled as well as they were able with splayed palm-flower pods, and the four mantas circled on the water. Cal was glad he had recovered enough of his strength to make a decent show of it. Six months ago he would not have been able to lift the crude oar, let alone use it effectively. He owed his resurgence to Nacre - the planet, not the raft - that had been inhospitable to man's physique but excellent for his spirit.
No - the planet had been no more than the locale. The benefit had been due to the friendship of two people - these two people - that had faced him back toward life.
He continued to row. His arms were tire
d, but the thought of that approaching wave kept him working. How had mantas known of the tsunami? They could not have detected a shock wave in the water, because the wave was the shock. Yet he was sure they were correct, for they did not make mistakes of that nature. Something important would happen with the water, and if not a wave it was because he had misinterpreted Circe's message. There must have been a vibration that their peculiar eyesight had picked up, or a rathation typical of large land movements. Something that not only signaled trouble, but allowed the mantas to judge its time of arrival. There was still much to learn about these fungus companions. And much to learn about tsunamis.
Of Man and Manta Omnibus Page 25
