The Yunnanozoon was one of the most significant finds in the entire Chengjiang Biota. Countless papers and research documents had established its role as the transitional link between invertebrates and vertebrates — the ancestral form from which all fish, amphibians, and mammals descended. Humanity included.

The New York Times had once published a memorable line about the discovery: "If the Yunnanozoon had died young, the central nervous system of animals would never have developed, and the Earth would remain as forever lonely and silent as the distant moon."

Now a catastrophe had brought the end of the world. At this inflection point in history, what was unfolding might be the sixth mass extinction — or it might be another explosion of life.

Extinction. Explosion.

Hard to judge in the short term. Impossible for Shen Cong to call with certainty.

It felt like an explosion — the Cambrian Explosion was the precedent, and evolved beasts were proliferating in exactly that kind of eruption. But it felt like extinction too — the fifth mass extinction, the one that ended the dinosaurs, had been caused by an asteroid impact; a meteor shower had now knocked humanity off its throne in the same fashion.

Either way, he hoped for explosion. Nobody wanted to be extinct.

He hoped, more specifically, to become the Yunnanozoon himself. The founder of a new era. The ancestor of a future civilization.

Even if he didn't currently have a girlfriend.

"If the Lv1 era truly represents a transition toward metallic form, then Lv0 could be defined as the 'Lv0 — Gradual Transformation Phase,' and Lv1 as the 'Lv1 — Invasion Phase.' The Activity core undergoes metallic transformation, then begins invading surrounding body tissue. And then — would Lv2 be the 'Lv2 — Metal Phase'?"

He opened the Apocalypse Journal and typed out his reasoning: Could metallic transformation be a phenomenon analogous to the 'phosphatization events'?

Near the boundary between the Precambrian and Cambrian, Earth had experienced two waves of life's explosion — corresponding precisely to two phosphatization events, periods during which phosphate minerals formed and accumulated in the oceans.

Phosphorus…