Episode 4: The Invasion to the Unknown Land, Part 2

After many organisms began colonizing the land, they adapt to become even more specialized for a terrestrial lifestyle. These changes lead to an impressive change to organisms and terrains alike.

Terrestrial Forest
Forest biomes are one of the most diverse ecosystems one can expect, supporting millions of all kinds of organisms. The forest varies between local climates. Similar to the marine forest, on this planet, the forests consist of many species of organisms derived from platyphyllophytes, a species of early land plants.

From being able to produce rigid cell walls and the abundance of carbon dioxide they can directly take up from the atmosphere, becoming gigantic on land is not a hard task. Over time, as they become more adapted to terrestrial life and become bigger, their roots, instead of only attaching to the surface, penetrate into the ground. This results in more weight support and an easier source of water within the soil. From this point, they branch off into two groups.

One group grows bigger and bigger, dwarfing any other of their kinds. Unlike their marine ancestors, instead of growing from primary meristems at the shoots alone, they are capable of a secondary growth within their stem, similar to many trees on earth. The lateral growth makes their stem and roots thicker as they age, making them able to support even more weight. They also capable of branching their apical shoots into several branches, which offer more space for leaves to grow from, thus increasing photosynthetic capability. The cells on the stem, however, lose the photosynthetic capability but are now optimized as supporting structure and storage. Their vascular system, evolved from their tubular mesohyl system, is used to transport water and sugar easily throughout the whole body. Their great height also means nothing at that time could reach the top parts, protecting both the leaves and the reproductive organs.

These massive tree-like members are named Xylodendron ("Wood Tree"). They are able to spread quickly across the lands due to not being eaten by any creature.

The other group, however, doesn't become a towering organism like their cousins. Instead, they become a massive bush with many branches sporting thick foliages. Each branch sports conical foliage that can grow as big as one meter in diameter. Similar to their ancestors, each growth segment branches three branches. When more branches accumulate, the bush becomes more and more spherical. However, the branches are generally low-lying, easily reachable by any organism. Unlike any of their lineage, they sport very small leaves but the amount is innumerable. Due to their massive bush, the reproductive organs at the center stem are easily obstructed. In response, the stalk bearing male gametangia lengthens to an incredible length of over three meters while the female gametangia become a massive bowl to increase the chance that the sperms landed on the female gametangia and fertilize the eggs.

From their multi-pointed star-like shape of the foliage, they are named Asterodendron ("Star Tree").

Terrestrial Meadow
In the meadow, low-lying shrubs and plants span across the horizon. Sometimes, trees can be found but not in a great number like in the forest, oftentimes as a lone tree in the middle of the plain.

Dominating the landscape is a species derived from thalassophytes that spread deeper and deeper inland. From their small size, dehydration is not a severe problem, making them able to thrive in a location with low precipitation. They can also grow another genetically identical plant from their roots. This makes them able to spread across the land very quickly. Each plant body can also produce gametangia, increasing the chance of pollination. The sporangium also shrinks in size, becomes lighter, and develops several large leaves, mainly to be carried by the wind so that they can colonize an area far away.

These fast-spreading plants become the main producer of the plain. Because of their winged sporangium, they will be called Pterocarpophora ("Winged Fruit Bearer").

Coastline Swamp
The coastline swamp is a location along the coastline heavily populated by several plants from several clades, both the terrestrial and marine plants. They form a dense forest, which in turn, easily provides many resources and shelter for many terrestrial and marine animals. Even though the forest forms after the first animal becomes terrestrial, it becomes a place where transitioning to land occurs very easily due to the massive amounts of plant lives within the area, both on land and underwater, providing nearly unlimited food sources.

Plant lives that live in the area consist of but not limit to platyphyllophytes, xylodendrons, asterodendrons, thalassophytes, euchemophytes, and sometimes many species of phyllostome lineages.

Terrestrial Animals
With the emergence of terrestrial biomes, resident faunas begin to adapt to the changing environments.

The first land animals who arrived on the beach of western Solus, the aspidopods, were a detritivore, now become specialized in response to massive food sources of various kinds. This separates them into three clades with their own subgroups. These clades, however, share two important traits that differentiate them from their ancestors; an ability to lay eggs covered in the amnion, which prevent the eggs from desiccation, and internal fertilization, which essentially cut ties between the creature and water. The eggs normally hatch into a larva that looks very similar to their parents and doesn't enter metamorphosis. The eggs, however, vary between clades.

One clade stays true to their ancestors, being a medium-size detritivore, feeding on fallen leaves and logs on the ground within forests and swamps, though some become a generalist. They are capable of burrowing into the soil if faced with danger. They lay small eggs with chitinous eggshell in a burrow they dug.

This clade is named Euaspidopoda ("True Aspidopoda") from its similarity to the ancestors of the clade members.

Another clade takes refuge on the treetop, using the height as a protection against potential predators. They evolve hooked claws on their legs, increasing gripping strength. Similar to their marine cousins, they have strong mandibles used to munch through the leaves of the land plants. They lay their soft-shelled eggs on a leaf of xylodendron. The larvae are very developed when hatched and immediately go after food sources, whether it be the leaf their eggs are on or other smaller creatures, depending on species.

From them living on the treetops, they are called Phylloscansora ("Leaf Climber").

The third clade branched from aspidopods roams the giant plain of Solus. From living in the open, they adapt to become larger as a means of protection against predators, however, predators derived from this clade also has large body size to tackle the giant preys. Unlike their relatives, this clade lays egg covered in an ootheca. Each subgroup takes care of their ootheca differently.

From them roaming around the great plain in search of food and water, they are known as Aspidobatida ("Shield Wanderer").

After the emergence and diversification of the first land animals, the aspidopods, for millions of years, the second group of animals makes landfall on the north-west Solus. These creatures are the small ambulopterids. At the current stage, they still have a hard time navigating the land due to their fins were not strong enough to support their weight, making them somewhat amphibian. However, their strange lung-like respiratory system makes transitioning to land not a major problem. However, it is further developed, with two additional valved chambers where inhaled and exhaling water is stored before being passed to the gills or exhaled, very similar to birds on earth. As time passes, they develop stronger, articulated legs supported with endoskeleton from their pelvic fins. With these legs, they can now support themselves and walk freely on land. Their pectoral fins are still used for gliding onto land after propelled themselves out of water when needed, such as when chased by aquatic predators, thus retaining their large size.

They are the second group of creatures to have set foot on land. They quickly spread across the land, They are called Archodraconida ("Ruling Dragon") from their body shape akin to that of a dragon and being a widely spread animal.

However, all of these happened mainly on Solus. On Lunas, situations are a bit different.