Episode 3: The Invasion to the Unknown Land, Part 1

Normally, the shoreline is a dangerous place, as creatures are unable to return to the water. However, as they become more advanced, some species may be able to live near the shoreline, which served them as a shelter against large predators and an environment with low competitors. At the current stage, creatures need to adapt to live near the shoreline first, and in the future, some may become fully terrestrial.

Current Stage of the Weather
With the marine forests and meadows appearing throughout the world, the oxygen level in the atmosphere greatly increased while the level of carbon dioxide, hydrogen sulfide, and Aether constantly drop, only able to be maintained by the giant volcano and the great font, which constantly pouring out the gases into the atmosphere.

With a reduction in the volume of greenhouse gases within the atmosphere, the average temperature drops to around 16°C.

Also, when the average temperature becomes lower, so does the ocean temperature, which disrupt the storm system of the planet. The central Solus, which is already dry, become even drier due to the storms become weaker, unable to reach the center of the continent.

Sandy Shore
Sandy shores are coastal shorelines where sand accumulates. At a first glance, the sandy shores seem to lack any sign of life. In reality, however, many creatures can be found hidden among the sand grains, including innumerable microscopic creatures.

From their nature of burrowing into the seafloor to hide from predators, helicaspids, mainly the detritivorous species, are somewhat adapted to live in this environment. In addition to their already waterproof chitinous shells, by digging into the sand, they can retain the moisture for a prolonged period without drying out and only coming out when there is a high tide. The scales on the tail also become chitinous, however, as the tail is used for swimming less and less, it shrinks in size and is now covered by three smaller shells. However, they will still lose water quickly to the air due to their gills. By internalizing the gills into a chamber on each side, the water loss is reduced. From they filtering the food and expelling the water from their gills, the gills are somewhat linked with muscle fibers, when internalized, the muscles now surround the chambers and help in contracting and expanding the gill chambers, increasing the breathing efficiency. Their legs, mainly used for digging, become covered in jointed shells to strengthen the legs, increasing the weight they can support. They still retain the hemocoel system, making them able to excrete the waste and toxin easily. However, as they become more terrestrial, they need to find a way to keep their gametes from premature death. As a countermeasure, they will return to the water to breed, however, instead of open-substrate spawning, the females lay eggs covered in sticky slime on a rock on the seafloor. This slime helps retaining water to prevent desiccation if the eggs were happened to be laid close to the surface.

From these creatures being the first animal to colonizing the land, they are called Aspidopoda ("Shield Foot").

In the shallow water near the beach, the chemophyte meadows can occasionally be found. Occasionally, the patch expands into the intertidal zone, causing some of the plants to be exposed to the air during low tide. Unlike the sporophyte, the gametophytes generally live submerged underwater, meaning they don't have a layer of cuticle covering them. When they are exposed, they quickly dry out. Over time, the gametophytes of these chemophytes develop a cuticle layer to cover themselves, thus reduce the water loss. During the high tide, this type of chemophyte is capable of expanding deeper into the intertidal zone. Being in contact with the air more and more, the chemosynthesis normally dormant during the gametophyte stage now becomes active during this stage as well. Now, the only factor that limits them from completely become terrestrial is reproduction. Similar to their cousins in the deeper water, their sporophytes also settle on the seafloor, however, instead of developing into a large sporophyte, the zygote develops into what looks like a ball of rock that grows several leaves. After two weeks of development and the condition is suitable, the ball, or "sporangium", will burst open, releasing innumerable spores of both genders into the water. As they become more terrestrial, they need to use winds to carry their sperms, or now as "pollen grains", to the female gametangia. They adapt by elevating the male gametangia and make the pollen grains easily blown by the wind while the female gametangia stay near the ground level and enlarge to increase the chance of pollens making contact and fertilize the egg cells. After fertilization, the sporangium develops on top of the female plants and bursts open after the development period, releasing spores into the air, which greatly increases the population of the plant.

This makes them one of the first terrestrial plants which will contribute greatly to the terrestrial food chains in the future. They are named Thalassophyta ("Sea Plant").

Though, some beaches are not covered in these newly evolved plants and are taken over by ancient species instead. These species are barely different than their ancestors. When drifted ashore, due to their rather simple body systems, they are able to survive on the shore for a prolonged period. Over time, they evolve the thick ectoderm to lengthen the time before they dehydrate even more. And also, similar to many species on this planet, they develop sexual reproduction. In a similar situation to their cousins that colonizing the land, they evolve a long stalk that bears a male gametangium with a female gametangium at the lower elevation. Unlike thalassophytes, however, an individual can have both gender and the fertilized zygote directly develops into another plant without entering alternation of generations.

From deriving from their ancestors while barely change over millions of years, these plants are named Euchemophyta ("True Chemophyte").

Rocky Shore
Rocky shores are coastal shorelines consisted of rock formations. The hard rocks provide stable bases for organisms to anchor themselves against the rock. The rock formations sometimes result in tide pools, a pool of seawater that is separated during the low tides. Due to the stronger base and the presence of tide pools, rocky shores are abundant with more complex marine lifeforms.

Some of the lifeforms on the rocky shore are a type of lithozoons that expand horizontally, covering a large area on the rock formations. These variants have a small slit that is shut when they are not submerged to prevent desiccation

Some other inhabitants are a clade of small polyphyllophytes. As their small size makes it harder for them to compete with other of their kinds in deep water, thus they are able to survive at the shallower zone where other polyphyllophytes struggle to. Over time, they expand onto the intertidal rock formation. Within this zone, they need to adapt to being exposed to sunlight. Their cellulose cell wall greatly decreases water loss, however, it is not enough. Similar to many species that come onto lands or are constantly exposed to the air, they thicken their epidermal cells, especially the upper epidermis, and covered them in another layer of waxy cuticle. However, the thick layer of cuticle makes water and gases unable to pass into the leaves. By developing openings, or "stomata", as a way to exchange gases and water from inside and outside of the leaf. Alongside the stomata are guard cells, a special type of cells that controls the state of stomata on their leaves, which generally keep the stomata the upper epidermis shut while periodically open and close the ones underneath the leaves unless they are submerged in water. And for reproduction, similar to the other two types of first land plants, they develop a stalk bearing male gametangia while the female gametangia are positioned lower. Unlike the other two, however, the sperms can swim on their own to the female gametangia when submerged, or are carried by the wind when exposed to the air.

From their low flat to the ground stature, they are named Platyphyllophyta ("Flat Leaf Plant").

Another type of the rocky shore inhabitants is a clade derived from ichthyoidmorphs. Unlike their ancestors, the members of this clade are mainly sessile, though their larvae are capable of mobility, similar to the life cycle of phyllostomes. They attach themselves to a rock surface, mainly inhabiting the highest elevation. They are also considerably smaller than their ancestors, with their size comparable to that of phyllostomes. Similar to the phyllostomes, they evolve several appendages. These appendages are lined with gill-like filaments to increase Aether exchange efficiency. After the water level become lower than their body, they will start sticking these appendages out of their shell to gather Aether, and retract them back after around an hour to prevent desiccation. And during a high tide, they collect water as much as possible to fuel their Aethersynthesis.

Their new body shape earns them the name Lithoidmorpha ("Stone-like Form").