Second Step.
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//Water is warm and continuous. As your eyes adjust, you notice a subtle ripple in the current. Slender, transparent creatures drift past, oblivious to your presence, yet carrying the future of an entire planet within them.
//In this post, I will present to you the earliest animals, as well as the creatures whose lineages lead to the colonization of land.
//The first animals resembled transparent worms. They possessed the rudiments of a nervous system, two pairs of simple eyes arranged in a trapezoid shape when viewed from the front, a mouth, gills, and a circulatory system consisting of one or several vessels running along the body and adjacent to the stomach and gills. They stayed near the water's edge and could not move against the current, which classified them as zooplankton.
The next two worms were not much different. Outgrowths formed around the mouth, followed by tentacles that helped capture food particles. Then, the first jaws developed along with a capsule for the main nerve ganglion - the future brain. These changes were followed by the complication of the jaws, the accumulation of more muscle mass around them, and the tentacles became longer and more controlled. The first pair of eyes developed into an eyespot/optic cup, while the second pair began to evolve into structures resembling compound eyes.
Later, a tube similar to a gladius developed from the "proto-skull" and along the body, to which muscles attached, allowing the animal to move faster and with more control, though still with the current. The creatures could hunt others, but they still stumbled upon most of their food by chance. The appearance of jaws and long tentacles helped hold large pieces of food and bite through them.
The subsequent changes led to the capacity for active predation and swimming. Tentacles with hard bristles serving as teeth helped in capturing and holding prey. The jaws became more complex and powerful, and the gladius divided into segments, which could be called the first backbone. The head acquired a distinct shape and was the first well-developed segment of the body. Pulsating vessels appeared for better blood pumping. The eyes moved to the same level and also split by function: the first pair processed information in front of the creature, while the second pair looked at the sides and partially behind, taking on an elongated shape. The creature also gained its first coloration, which was partially for camouflage. Towards the rear of the animal, a semi-circular tail forms, narrowing at the base. Over time, the body's transparency decreased.
With the division of the backbone, a weak segmentation of the outer integument also appeared, along with the development of a fin-plate on each segment. Due to a more active lifestyle, two hearts developed on each side. Vessels ran to each fin, and the further the fins were from the middle of the body, the longer the vessels were. The stomach became more complex, which helped extract more nutrients. The tentacles with teeth developed internal plates that helped strengthen the tentacles and control them more precisely. The upper pair of tentacles had two plates each, covering the tentacles from the outside, and were attached to the upper jaw. The lower pair of tentacles had three such plates each and were attached below the eyes to the cranium. Later, zygomatic bones developed over this attachment point. Somewhere at this stage, the first pair of eyes already possessed a lens. The second pair of eyes had the first clusters of simple eyes. It is important to note that the compound eyes developed by fragmentation of the simple eyes and later transformed into complex structures.
In the subsequent stages, there was an increase in size, fin development, and heart power; the stomach became more efficient, and the first primitive lungs formed from the gills and stomach. The upper mandibles became smaller and more compact, almost constantly pressed against the upper jaw. The lower mandibles also shortened, but their function still included holding prey, while the upper ones helped to gnaw or also hold already separated pieces of food.
The creature's coloration acquired rusty-green shades, and a bright spot was located on the tail. Also, black spots were scattered on the head and on the first few segments, one of which was outlined with a white circle. The first five fins increased in size, the next three decreased in favor of maneuverability, and the last three also increased for speed. All of them helped to control the body in three-dimensional space.
Next comes the split into the Kishulunar branch [fish analogues] and the Sudfalunar branch [arthropod analogues].
Their first major difference lay in the structure of their jaws. In Kishulunars, the jaws were connected both by a 'jaw arch' consisting of two small bones, and in the future temporomandibular joints of later creatures. Also, in their lineage, both mandibles fused with the main jaws. In Sudfalunars, the connection between the lower and upper jaw occurred due to the jaw arch, whose lower bone was fused with the lower jaw. The temporomandibular joint was developed, but allowed some distance from the upper jaw.
In both groups, the middle three fins fully reduced, while the rest developed into lobe-finned structures and flippers, or plate-like fins. Kishulunars retained three pairs of fins in the pectoral girdle, two of which were preserved during the colonization of land, with one of them having a multi-plated structure. In the pelvic girdle, two pairs remained, one of which did not develop to a ray-finned structure, and after the land transition, a vestige remained from this pair in the form of post-pelvic bones. In Sudfalunars, the first two pairs of limbs developed into auxiliary flippers, the next three into pectoral limbs, and the last three into pelvic limbs.
In Kishulunars, the second pair of eyes reduced and remained as a thin, short strip around the eye on the far side. In Sudfalunars, the second pair of eyes continued to develop alongside the first.
//[EXIT]_
//Later, I will show you the evolutionary treeāa cladogram of Kishulunars in a sketch format. There is no cladogram for Sudfalunars, or more precisely, Sarsuards yet, which I will certainly fix in the future. For now, my thoughts are scattered regarding their evolutionary capabilities, and figuring it all out will take a long time. I will also be drawing some individual species, both the 'feesh' and the roaches that belong to larger groups, or even scenes and illustrations of their lives. [But to be honest, in my current state, Iād be happy just managing to draw anything at all].










