Space 2: Life: The Paleozoic

🟠 Cambrian sea monsters to the Permian mega-extinction · 500 – 252 million years ago

🟠 Dot 1 · 538 – 486 million BCE

The Cambrian: An Anomalocaris (uh-NOM-uh-LAIR-iss), a predator as big as a beagle, cruises above a seafloor crowded with five-eyed, spike-encrusted experiments in evolution.

📍 Address: Space 2 · Dot 1

For three billion years after life began, Earth's oceans were basically soup: drifting specks, slime mats, soft, slow, boring. Then, about 540 million years ago, something snapped — and in a geological eye-blink the seas filled with animal life of every shape evolution could imagine. It's called the Cambrian explosion, and it was evolution's first wild art show. Nothing was standardized yet. Some animals had FIVE eyes. Some stood on stilt-legs like a walking tent. Some wore spikes and armor like knights. And cruising above this strange garden swam the first great predator the world had ever known: Anomalocaris — 'abnormal shrimp' — as long as a beagle, with two spiny grabbing arms in front of its round, tooth-ringed mouth, and a body built to swim down and snatch. For the first time in the history of life, animals were not just drifting and eating — they were HUNTING each other. And that changed everything, because eyes grew sharper to spot the hunters, armor grew thicker to survive the bites, and every animal was pushed, for the very first time, to get better or get eaten. The arms race of life had begun.

🌍 Find it on the globe: Burgess Shale, high in the Rocky Mountains of British Columbia, Canada

❓ Orient question: If you could design an animal from scratch — no rules — what would you build?

🟠 Dot 2 · 486 – 443 million BCE

The Ordovician: A straight-shelled Orthoceras (or-THOSS-er-us), longer than a giraffe is tall, drifts silently toward a hand-sized trilobite.

📍 Address: Space 2 · Dot 2

In the Ordovician ocean, the rulers of the sea wore their skeletons on the OUTSIDE. Meet Orthoceras: imagine a squid wearing a straight, pointed spear of a shell — a cone taller than a grown giraffe, hovering silently in the dark water. Inside that spear lived the strange part: an animal related to today's nautilus and squid — tentacles reaching out of the shell's open end, jetting backward by squirting water. Now watch the hunt. Drifting near the sea floor, small trilobites — beetles of the ancient sea, curled armor-plated bugs of the deep — scuttled through the mud. One of them looks up... too late? The giant cone glides down without a ripple. No roar, no chase — just silence, then shadows. That was the Ordovician: an ocean colder and deeper than today's, ruled by quiet, patient hunters. And while the giants patrolled above, something was quietly happening in the shallow seas that would matter more than any monster: the first coral reefs began to grow, and the first fish — soft, jawless, feeble little things — appeared. Nobody watching would have bet on THEM.

🌍 Find it on the globe: Ancient seas — fossils now found in the deserts of Morocco

❓ Orient question: How long is 'long ago'? Could you even imagine a sea creature taller than a grown-up giraffe?

🟠 Dot 3 · 443 – 419 million BCE

The Silurian: Two Pterygotus (teh-RIG-oh-tus), sea scorpions bigger than a person, circle each menacingly other above a reef crowded with armored fish.

📍 Address: Space 2 · Dot 3

You know scorpions: small, armoured, tail up, sting ready. Now build one that could look a dinner-table adult in the EYES — two feet of armoured monster, paddles the size of flippers, eyes like headlights, and two front claws like giant garden shears. That was Pterygotus, the sea scorpion of the Silurian — technically not a scorpion at all, but an arthropod, cousin of crabs and spiders, and one of the largest arthropods that ever lived. In the shallow, sunlit Silurian seas, two of these giants drifted toward each other above a reef crowded with armored fish. Why? Same reason big animals always meet: TERRITORY. No sharing a good hunting reef. These two rose up, paddles spread, claws open — a slow-motion battle of two knights in full armor, while the fish below scattered like scared minnows. The winner gets the reef; the loser drifts off, dented, into the open water. And somewhere in that same crowded Silurian sea, the first jawed fish were figuring out their new invention: TEETH. The age of giant bugs was at its height — but the age of fish was coming.

🌍 Find it on the globe: Ancient seas — fossil beds in Scotland and Sweden

❓ Orient question: What's the biggest bug you've ever seen? Now imagine one bigger than your dad.

🟠 Dot 4 · 419 – 358 million BCE

The Devonian: A Tiktaalik (tick-TAH-lick), a flat-headed fish with primitive wrists, heaves itself from predator-filled shallows toward empty land.

📍 Address: Space 2 · Dot 4

The Devonian was the age when fish became KINGS. In these seas swam Dunkleosteus — as long as a car, armored like a tank, with a head shield of solid bone. But here's the nightmare: it had no teeth. It didn't need them. Instead, its jawbones themselves ended in sharpened bone blades — self-sharpening guillotines, and a bite force that could crush ANY shell in the ocean. Dunkleosteus was the first super-predator fish, and it ate armored prey for breakfast, cracking them open like walnuts. Around it, the Devonian sea was an arms market: some fish grew heavier armor, some grew faster tails, some — like the famous lungfish — grew a strange new trick: the ability to GULP AIR when the warm swamps ran low on oxygen. And that little trick would matter more than every giant in the sea. Because from those air-gulping fish, some descendants hauled themselves up the mud toward the green world beyond the water — the first forests were rising on land, the first insects were humming, and the door to the whole dry Earth was standing open. The fish were already eyeing the exit.

🌍 Find it on the globe: The Devonian seas — fossils now weather out of the cliffs of Ohio, USA

❓ Orient question: If you had to wear your skeleton on the outside, what size could you never be — and why?

🟠 Dot 5 · 359 – 298 million BCE

The Carboniferous: A mouse-sized Hylonomus (hy-LON-oh-mus) hides its shelled eggs amidst swarms of giant dragonflies in a swamp of towering trees.

📍 Address: Space 2 · Dot 5

Welcome to a Carboniferous swamp, 300 million years ago. Scale everything up. The ferns are TREES, ten stories tall. The horsetails are as thick as telephone poles. Dragonflies as big as hawks drone overhead, and millipedes the length of a car stroll past your feet. How could bugs get so huge? OXYGEN — the air had more of it than almost any time in Earth's history, and insects breathe through tiny holes in their sides, so richer air means bigger bugs. And the swamp itself? It was drowning and regrowing, over and over, for millions of years. When the giant ferns died, they fell into waterlogged mud, where the rot-eating bacteria — used to doing their clean-up work — simply couldn't finish the job. Layer upon layer of half-dead forest pressed down, buried, squeezed, and slowly turned into something dark and dense and hungry for a match: COAL. Every lump of coal — the stuff that powered steamships and Edison's lightbulbs — is a compressed forest of giant ferns older than the dinosaurs. When people call coal 'buried sunlight,' this is the burial they mean.

🌍 Find it on the globe: The coal swamps — now the coalfields of Pennsylvania, USA and England

❓ Orient question: Have you ever picked up a rock that burns? Why do you think old swamps turned into something that catches fire?

🟠 Dot 6 · 298 – 252 million BCE

The Permian: A sail-backed Edaphosaurus (eh-DAF-oh-SORE-us) crouches in thick bush, hiding from a predatory Dimetrodon (di-MEH-tro-don) stalking the dry, sunbaked plain.

📍 Address: Space 2 · Dot 6

This is the worst disaster in the history of life on Earth — and it starts underground. About 252 million years ago, in what is now Siberia, the crust cracked open and volcanoes began to erupt. Not ordinary volcanoes — flood basalts: cracks that poured lava like faucets, for THOUSANDS of years, covering land the size of a continent. And the lava burned through OLD coal beds as it went, blasting out ash and poison gas: the sky dimmed, the oceans acidified, the air itself grew foul. Then the true killer, the silent one: the warming seas lost their oxygen, and dead zones spread from the coasts like bruises. When it was over — the Great Dying, the Permian extinction — about NINE of every ten species on Earth were gone. The trilobites: gone forever. The giant sea scorpions: gone. The lush coal swamps: gone. Recovery took millions of years. It was the closest life has ever come to losing everything... and it didn't. A few hardy survivors hung on — stubby little reptiles, tough little mollusks — and from that ragged remnant, life rebuilt itself. One of those survivor families, small and humble, would one day grow into Tyrannosaurus. That's the next space.

🌍 Find it on the globe: Siberia — the frozen ground still hides the scars

❓ Orient question: What could kill almost EVERYTHING on Earth — and yet fail to kill anything at all?