In Wonderful Life, Stephen Jay Gould forcibly argued that the decimation of spectacular invertebrates at the end of the Cambrian was a matter of luck. Anomalocaris wasn’t inherently inferior, or the survivors objectively superior. The quirks of life simply stacked the deck against some forms of ancient life while giving a pass to others for intricate ecological reasons we haven’t been able to discern.

Whatever the reason they disappeared, though, the extinction of some Cambrian forms had a dramatic effect on the history of life on earth. The species that ultimately lost – such as Anomalocaris – embodied other, ultimately unrealized evolutionary possibilities. Imagine what the seas would look like if such bizarre animals survived to