Apokalypse-Schwamm

*Symphon apokalupsis*. An unassuming button-shaped sponge that may be an omen of mass extinction.

1. Simplicity

Among the earliest animal forms on Earth, sponges are a group of cells that live between two membranes and work together to pump water. Sponges on this world are similarly elegant.

2. Tolerance

Due to this simplicity, sponges tolerate low oxygen and high temperatures better than many other organisms. They also benefit from elevated death rates, which floods the water with decaying matter.

3. Role in mass extinction

Biospheres dominated by sponges may be an indicator of a recent or ongoing mass extinction. After Earth's first major die-off during the Ordovician period, some 85% of species went extinct, leaving a world ruled by sponges. The popular existential terror franchise "Life Is Only Pulse" is set in a fictionalized version of this time period.

Assessment: possibly a warning sign of planetwide ecological collapse. Possibly not.