Update 5 - The Halgatronian Epoch
This epoch is named after the
Halgatrone, the first true land plant and a landmark in the evolution of life on the planet. Being frequently buried by sediments, and with a lack of microbes adapted to breaking down the dead Halgatron growths, it has left behind many immaculate fossils from this era.
The climate fluctuated chaotically throughout this epoch, as various mechanisms and feedback loops competed with each other to strengthen or weaken the greenhouse effect of the atmosphere. It also seems that the large southern landmass was beginning to break up, altering ocean currents. The full story has been impossible to fully decipher from the fossil record, but variability in temperature and relatively-extreme weather was a trend that increased towards the end of the epoch.
The aforementioned
Halgatrone was now spreading rapidly across parts of the land, and away from competing plant species. With an ability to survive only on rainwater, and tolerance for short dry spells, it could grow far from the swamps and riverbanks that had limited its ancestors. However, the Halgatrone was limited by its rather primitive roots, which it now relied on for nourishment, and it was a slow process to colonise land that was almost completely devoid of soils - being mostly gravel, sand and exposed rock. And with no means to fight against gravity, it grew horizontally across the land surface, leaving it vulnerable to being buried by dirt, sediment, or - more rarely - snow. However, it’s development of airborne spores was a key breakthrough, as it enabled the Halgatrone to gain a foothold on many separate small landmasses by the end of the epoch, even if overall coverage was limited. Viewed from space, the land masses would still be a gold-grey colour at this time, with hints of green only in a few flood plains and coastal marshes.
The Bigster family suffered a big decline in this era, partly due to unpredictable climate, but also due to the appearance of two new groups of Swimstermorph predators, which adapted to resist the poisons present in this group. The
Scrapers also evolved teeth to gouge chunks of flesh from the much-larger prey, while the
Lancers adapted the small ‘harpoon’ of their ancestors as a tool to inject digestive fluids into their victim - which would cause grievous internal damage, and indeed often proved fatal. But while Scrapers could perform hit-and-run attacks, gathering a few scraps of food, Lancers had to remain impaled in their victims for some time in order to reap the full rewards, leaving them vulnerable in turn to other predators. For this reason it seems that the smaller and simpler Scrapers had a slight edge in the poison-hunting niche. Both groups could opportunistically hunt other animals, but there too they faced increasing competition.
All surviving branches of Bigster show a decline in numbers by the end of the epoch. The Flapmellesters seem to have had the strongest population, as they at least had some ability to swim to escape attack, and had less-vulnerable offspring. Ironically, the non-poisonous Drifters were now best protected, thanks to the Clinger colonies attached to their undersurfaces, but were increasingly vulnerable to being blown into cold waters or onto land, either of which would rapidly prove fatal.
Clinger species however had a renaissance thanks to the appearance of the
Thoraxenia, a descendent of the Slugster and relative of the Clinger. Complete fossils of Thoraxenia are vanishingly rare - it is theorised that upon death, the soft body of a Thoraxenia would normally be partly digested by its Clinger passengers while they waited for another animal to attach themselves to. Nonetheless, it can be inferred from the pattern of Clinger fossils that Thoraxenia was common in warm coastal biomes of this epoch. It is believed to have evolved structures to actively feed its Clinger passengers and encourage them to remain attached, giving protection from attack while it went about its business of slowly picking algae and detritus off the seafloor. Though not an indestructible partnership, it evidently proved successful enough, and by the end of this epoch it seems likely that host and passengers evolved to co-ordinate the budding of offspring, ensuring newly-budded Thoraxenia started out with Clingers already attached.
Flentatail was a new predator adding to pressures in the tropical biomes in this epoch, and its appearance is a significant event in the evolution of the Crawlzorids. It is the first known member of its clade to have an active circulation system, with rear tentacles adapted to serve as both swimming appendages and as gas-exchange organs. It was thus a larger and more active creature than its cousins. This, combined with its primitive vision and barb-lined hunting tentacles, made it a formidable predator of the time. Facing Harpazo and Lancer as its main competitors for free-swimming predator niche, Flentatail would be more successful in capturing prey with its flailing limbs - its rivals had similar poor eyesight, but for their mode of hunting this proved more of a drawback. Flentatail was able to inflict serious damage on any of its soft-bodied opponents in a duel. Finally, Flentatail was also able to reproduce in much greater numbers when conditions were right. However, like its cousins the Horgazorgs, the Flentatail was not particularly buoyant and would sink to the seafloor when not actively swimming against gravity. This made it unable to penetrate far into open expanses of ocean, where the Swimstermorphs still had the advantage.
Horgazorgs diversified further with the appearance of the
Gallahorg, a group that simply seems to have been better at surviving in cooler waters, likely a response to erratic climate of the time. This was nonetheless significant as it meant the first arrival of the Crawlzorids in colder biomes outside the tropics. Here Gallahorg was a successful omnivore and generalist. There is also evidence that some varieties of Gallahorg were able to survive higher water temperatures than normal, though it’s not clear what evolutionary benefit this bestowed - perhaps, it allowed these creatures the minor niche of exploiting volcanic systems that occured in shallow water, feeding on bacteria growing near hot vent plumes, though this remains controversial.
Slinkyurt is the final new branch of Crawlzorid from this epoch. In contrast to its ferocious cousins, Slinkyurt appears to have been moving towards the role of sessile planktivore and ambush-predator. A key adaptation was the ability to sense vibrations, giving it time to move its tentacles into position to prepare a strike. Fossils suggest this species was rather successful, one of the more common to be found in the tropical shallows.
Chillster is likewise the latest branch of Swmsterid to appear. Diverging from the highly successful Coolsters, the Chillster had an even-more efficient apparatus for trapping and digesting plankton as it swam. With the decline in Bigsters, it also made inroads into tropical regions and began to take over as the main free-swimming planktonivore of the oceans. In fact, Chillster likely had access to more energy than it could fully exploit; like many other animals of the time, it was limited by its primitive means of locomotion, its lack of an effective means of reproduction, and its lack of any real circulation system, putting a limit on how big and active these creatures could get - keeping them small in size compared to the majestic Flapmellesters, even as they greatly overtook them in population. Their sheer numbers nonetheless added considerable food for the Harpazo and Flentatail.
Aerotron is a remarkable among sea-based plants of the era, as it is believed to have been buoyant enough to rise clear above the water. Being lifted into the air would be a death sentence, as the plant could not survive out of sea water. However, it is theorised that large floating mats of Aerotron would combine together, with a large enough mass of tangled fibers remaining underwater to act as a kind of anchor for the photosynthesising parts of the plant to remain just above the waves and out of reach of herbivores - forming strange floating mats of vegetation, licking above the waves in certain sheltered parts of the tropics.
However, like all free-floating sea plant-like lifeforms, this was a highly precarious lifestyle - firstly requiring water rich enough in nutrients to be able to grow, secondly being at the mercy of winds and currents which would often spell doom by being stranded on the planet’s vast tidal flats, or even carried far inland, or high up into the cold clouds. Aerotron was especially vulnerable to the increase in weather during this epoch, and was already struggling when the Kafkasus appeared.
Kafkasus was an Interesting development of the Moldus family. Rather than being purely a decomposer, it was able to actively attack and digest plant tissue - forming clumps of oozing matter that slowly moved through plant growths in slow-motion waves and ripples, smothering and digesting as it went. Kafkasus also had some ability to survive out of water, putting the tidal zone in reach, as well as the floating growths of Aerotron. Kafkasus growths were in turn a food source for inquisitive animals, but this was little comfort for the Aerotron. By the end of this epoch, it is believed only a few isolated pockets of Aerotron remained in isolated saltwater lagoons, where it may have formed a kind of accidental mutualism with growths of Kleptotron - leaching nourishment from the Aerotron in return for helping to keep it grounded to the lagoon bed and not blown away.
A final evolution to mention is the
Dodecaster, which for a long time was a puzzle in the fossil record as it left behind only jumbled polygonal armour plates. It is now believed to be yet another strange member of the Blobster family, and the favoured reconstruction is that of an oddly-geometric shaped animal, filtering plankton via gaps in the armour plates. Likely a response to the increasing number of predators around at this time, Dodecaster seems to have been moderately successful in the increasingly-crowded tropical biomes.
Species List + Stats
Notes:
Horgazorgavorga renamed to Gallahorg to avoid confusion!
EDIT: Something I forgot to stress in updates so far - this planet has seasons, and poles experience winters without sun, and summers without night. Some form of hibernation would allow these areas to be lived in permanently.
If some form of Moldus could get onto land, it would help create fertile soils. However, the pioneer land plants have steamrolled ahead of Moldus, which aren’t yet tolerant of freshwater.
Besides which, quite a few untapped biomes remain. The Deep sea is unexplored, but requires cold resistance and pressure resistance. It also contains volcanic vents which require heat resistance to exploit - so quite a few environmental hurdles there.
The atmosphere of this planet is more buoyant than Earth, and has aeroplankton, though not in as great abundance as the oceans. Life in atmosphere is possible, but will likely require water retention and freshwater tolerance, as well as cold resistance.
Announcing - Bonus Genes! Not player-specific bonus. You’ll find in the stats
‘Evolution Bonus: +1 gene’ next to some of the older life forms. What this means is if you evolve from this species, you’ll get 3 genes to spend instead of 2. This represents the accumulated genetic changes / genetic diversity in older groups. It’s also a handy mechanic to encourage people to fill out the tree of life in other directions
As an example, I am evolving from Vorzord and now have 3 genes to spend:
Bathyzord - Daftpanzer
Evolved from: Vorzord (Era 5)
Genes added (+1 bonus): 1x Cold Resistance, 1x Pressure Resistance, 1x Buoyancy
Description: The Bathyzord genus has evolved to exploit scavenging found in cold, dark depths of the continental shelf. It cannot yet dive too deep, but it can go far enough to avoid harassment from other animals and monopolise the scavenging that settles to these depths. To save energy while searching for food, it has evolved buoyancy sacs which develop from one of two specialised tentacles. While hovering just above the sea floor, other tentacles lazily push the creature along, ‘tasting’ for any scraps of food as they go. Bathyzords break with the 14-tentacle symmetry of their relatives, often having an odd number of limbs, each specialised for different tasks.