I've got a geologic timeline running along the walls of my new appartment, so I made some icons to mark the mass extinctions on it! They depict the Big Five, plus the End-Ediacaran extinction, some in a more literal fashion and some more metaphorically. Detailed look and explanations in reverse chronological order below the cut.
Cretaceous Paleogene Extinction: Meteorite hitting the Earth.
End-Triassic Extinction: Pangaea split by a line of fire to show the future mid-oceanic ridge massively erupting as the supercontinent breaks up.
The Great Dying: To depict the worst extinction of all time, I drew the Earth as a skull.
Late Devonian Extinction: The Late Devonian extinction may have been set off by the evolution of trees completely changing how the world's climate and cycles worked. By breaking up rock into soil they released massive amounts of nutrients into the environment, leading to anoxic waters. They reduced the CO2 in the atmosphere, causing a temperature drop. The knock-on effects of all this, possibly combined with a volcanic period, resulted in a mass extinction. To try and depict the trees indirectly killing life, I drew them literally killing it with their roots. Some of the victims are lobe-finned fish, jawless fish, brachiopods, trilobites, crinoids, and cystoids. Another root is turning into an ice crystal and another into a very eutrophic pool of algae-infested water.
Ordovician-Silurian Extinction: This one is considered to be the result of an ice age, so I drew a snow crystal. The middle part is also meant to be reminiscent of a bright star, in reference to the (not especially probable) hypothesis that it was set off by a nearby supernova.
End-Ediacaran Extinction: I really struggled with this one, as it's still fairly poorly understood, but is thought to involve a major anoxic event. But how do you clearly depict a lack of oxygen? It's not easy without resorting to drawing choking humans or crossed out oxygen formulas and such. Instead, I depicted the results of it: the disappearance of the Ediacaran biota and their replacement with the more familiar creatures of the Cambrian. This is a trilobite crawling over the fossils of a Dickinsonia, Charnia, and Tribrachidium.
