Panel 1: two Tiktaaliks (an extinct, 375-million-year-old fish that was the evolutionary link between fish and the first four-legged land animals) sit at the floor of a shallow sea bed. One of them angrily says to the other, “hey! You still owe me 20 bucks!”

Panel 2: the other Tiktaalik, to avoid paying $20, emerges from the water and steps onto land for the first time in history. The first tiktaalik is absolutely stupefied.