Epoch 2 - The Great Dying
This is an era in which budding diversity was suddenly and brutally snuffed out. It seems that for millions of years, sluggish movement of the continents had allowed a large amount of heat to build up in the planet’s upper mantle. Now one particularly massive volcanic hot-spot broke through a junction of ocean plates, in an area known as the Moddier Rift.
Beginning as an unremarkable area of volcanic smokers on the sea floor, the Moddier eruptions soon spread out and grew by orders of magnitude, until gigantic volcanoes rose kilometres above the waves - spewing out huge volumes of lava, gas and ash. At the height of the event, super-volcanoes were erupting almost every year, sending frequent tsunamis against the shores of the continents and devastating coastal biomes. Compounding the effect was the simultaneous opening of a rift between northern and southern halves of the Topican continent, causing further volcanism and creating another new volcanic island arc. The planet had not seen volcanic activity on this scale since long before complex life had evolved.
Ongoing for millions of years, the combined effects were devastating. A stratospheric layer of ash, frequently renewed by new eruptions, blocked sunlight, putting huge stresses on plant life and on plankton in the oceans. Poisonous volcanic gasses were dissolved in the water and spread by ocean currents around the world, putting further major stress on marine life and working their way into the atmosphere. A sharp spike in greenhouse gasses caused the global climate to heat up to dangerous levels, despite the lack of sunlight; equatorial water temperature soon exceeded 40 degrees celcius, which by itself killed off many forms of life and left the surface waters deficient in oxygen; the tropical regions became battered by near-constant hurricane-force storms, ripping up any large plants which still grew; in other areas, heavy rain and flash floods simply washed away plants and animals. The increased weathering of rocks by the extreme weather caused many areas of shallow water - previously the most bio-diverse habitats - to fill in with sediment, while also drawing down oxygen from the atmosphere through chemical reactions with the exposed rock. Combined with the reduction in plant life, oxygen levels plummeted - killing many large insects and arthropods - while carbon dioxide levels grew ever higher, encouraging the growth of poisonous anoxic microbes which only add to the cycle.
Whether by starvation, suffocation, poisoning, drowning, overheating, or the physical action of extreme weather, life has been devastated throughout the ocean and on all continents. No large animals or plants now survive outside of the deep sea. Most families of life were able to survive thanks to a few hardy species - almost all now concentrated in polar regions - but some have been lost altogether; the various Giant Fungus of Nessaria are completely extinct, as are the global lineage of Armoured Fish (including the recent crocodilian-like forms), Sea Scorpions (ancient, fearsome-looking aquatic predators), and many ancient reef-building species are also casualties, leaving the seas currently without anything resembling coral reefs.
Trilobites have been severely culled, losing most of their amphibious species - survivors only in isolated mountain lakes of Panzerna - and surviving with only a few, small, simple filter-feeders throughout the oceans, along with a few larger species adapted to life on the deep seafloor. On land, insects and arthropods have been severely thinned out, with no large arachnids surviving. As for the promising Tetrapod family, almost all species are now extinct - only a few hardy amphibious species survive globally, and the newly-separated region of North Topica is home to the only surviving Tetrapods which have by now adapted to live permanently on land, with thinly-shelled eggs; these are small, lizard-like creatures with very low energy demands, adapted to low oxygen levels and solitary lifestyles. More complex Tetrapod relatives had begun to appear before the extinction, with higher metabolisms and social behaviours such as shared burrows, but these creatures could not survive the turmoil of the last few million years.
While still appearing greenish from space, much of the land is now a warm, wet, windswept heathland, with hardy moss making up most of the vegetation. Deserts have shrunk, and the land has been fertilised by a dusting of volcanic ash, but there are no more forests; small vascular plants - with a mix of survivors from different families, seeds and spores now scattered all across the world - only grow in sheltered locations, and sheltered lakes are home to the last few remnants of kelp-like plants - though again, more complex forms of kelp that had begun to evolve have already gone extinct. Storms, floods and gigantic mudslides remain major problems for all surface biomes. Many inland lakes are completely anoxic, full of poisonous microbes. Microbial blooms have also taken over across the equatorial waters, which are now too warm and too low in oxygen for most complex organisms to survive.
For some species, there is an opportunity however; many new species of tiny insects and arthropods have adapted to low oxygen conditions and to exploit the new warm, moist heathland habitat. There has also been a surprise revival of
velvet worms - ancient arthropods, among the first colonists of the land - along with relative newcomers, many species of terrestrial molluscs - both with and without shells - that now slither through the swamps and moss. In the northern and southern oceans, with a thinning-out of fish and ammonite species, squid-like creatures from the deep have begun to adapt and compete for these niches. The deep sea vents, in places where they remain stable, are home to heavily-derived trilobite species and large annelid worms, making up the largest animals alive at the moment - living in coolest and most oxygen-rich waters that remain, while benefiting from volcanic minerals that have filtered down through the surface waters.
As this era draws to a close, the eruptions are beginning to cease, but the planet remains on the brink of a runaway greenhouse effect - the oceans are already on course to start slowly evaporating. Even as the ash haze in the atmosphere begins to disperse, the stormy hot climate is not conductive to large-scale plant life, without which the atmosphere will remain suffocating to any large creatures.
Nessaria and Imperia have now merged to form the continent of Nessperia, with a huge mountain chain hosting some of the last deposits of ice on the surface of the planet. Western Panzerna has already begun to merge with this continent. South Topica is sliding past Panzerna in the opposite direction, heading east, while North Topica continues a relentless march to settle ontop of the north pole. The new micro-continent of Moddier (largely comprised of dramatic landscapes of solidified flood basalt) is largely stationary.