"The amount of resources required for laying roots in the ground is very large, but if too much liquid water on the surface is obtained, it will affect the stability of the ecosystem. Therefore, I propose to obtain hydrogen and oxygen from the stratum to produce water as an element. The main source of acquisition."

"Oxygen can be obtained directly from the air. This planet is extremely rich in oxygen, but we cannot guarantee that there will be abundant hydrogen in the formation."

"Hydrogen can be obtained from outside the planet. We build gimbal creatures and send transport creatures to gas giants to carry a large amount of hydrogen resources back."

"The approved plan, but this can only be used as a supplementary plan for the lack of hydrogen resources in the formation. The colonization of this star system requires a lot of resources. If not necessary, try not to get resources outside the planet."

"Agree."

After simply formulating the underground expansion plan for the rhizomes, the thick and long main rhizome is bred. After reaching 50,000 meters underground, the one-sided vertical cloth is displayed, forming a network of intertwined roots in the ground.

This kind of expansion is not once or twice. The collectors have quite sophisticated experience in this area, and this kind of experience assists them in their rapid expansion underground.

There are multiple combustion chambers in the formation. These combustion chambers regularly extract oxygen from the surface, and then pour in the hydrogen obtained from the rhizomes. After the two are combined, they are burned to obtain a large amount of heat energy as an energy source. Water resources.

Before they knew it, the collectors quickly laid a network of rhizomes all over the ground of the planet, and the rhizomes were intertwined, replacing a stratigraphic structure of the planet.

Subsequently, the collectors began to extend the roots longitudinally, one facing the ground and the other facing the core, extending the rhizomes vertically in two directions.

In this process of expansion, some things caught the attention of collectors. They found some spherical objects in the stratum 10,000 meters deeper, that is, about 60,000 meters above the ground.

"What are these things?"

"It seems to be... an egg?"

"Be confident and change the question to affirmation. This is the egg of some kind of creature."

"If it is an ordinary stone, these small complex structures will not exist in these spheres, and they will be restored along the internal veins. The inside of the sphere is obviously the embryonic fossil of a certain organism."

The volume of these sphere fossils is small, about the size of a human thumb fingernail. Because these egg fossils are small enough, they can remain intact under the high pressure of 60,000 meters underground.

"Carbon and copper are used as the basis to build bones, interesting biological designs, and the ethnic group has no material ideas in this regard."

"These things have basically confirmed that animals existed on this planet for a certain period of time."

"But now these animals are all extinct, what caused their extinction?"

The collectors were puzzled. After the Rhizome surveillance network on the surface was completed, they determined that there were no animals on the planet, but the fossils showed that animals once existed on the surface, which means that animals existed on the planet. The incident led to their extinction.

"I don't know, these fossils have not left us with more information. The lack of understanding of them prevents us from simply deducing the cause of their death from the chemical composition."

"But it is certain that it should be the extinction of animals caused by a large-scale or even a global disaster. We can try to find the answer from the changes in the strata."

Collectors first thought about the extinction of animals caused by terrifying natural disasters such as asteroid impacts, super-giant volcanic eruptions, and so on.

"That's it. The dividing line between animals and plants is only plant fossils above this level. According to the half-life determination, it is between 100 million and 150 million years away from our current time point."

"There is no obvious difference between the two formations."

Comparing the upper and lower regions, there is no obvious segmentation trace. If it is a global natural disaster, it will inevitably leave traces in the stratum, but it does not.

"This is weird..."

"The reduction of animal fossils is gradual, and may not be the result of large-scale disasters. It is more like being eliminated by natural selection."

Some collectors suggested it, but it was soon questioned by the same clan.

"Eliminate? Who eliminated them? There are only plants on this planet..." When this comrade was questioning, he suddenly reacted, "You never want to say that plants eliminated them?"

"Is it possible? Plants are inherently weaker in subjective initiative than animals, so plants can only be producers of food chains instead of consumers. Plants on this planet are also less subjectively active than animals, so how can they occupy in biological competition? The upper hand?"

The collector explained his thoughts, "It may be because of fire."

"Fire?"

The oxygen concentration on this planet is terribly high. Plants are also oily plants. It can be said that they are petrol plants in the shape of plants. Only a single Mars can cause a fire for hundreds of kilometers.

Animals are indeed much stronger than plants in terms of subjective initiative. However, no matter how strong animals are, they are not as strong as flames. The basic units of genes will degenerate and decompose in high temperature environments. This is not something that can be solved by natural selection evolution. It's a difficult problem, but it needs to be specifically targeted for cooling design.

Therefore, a large area of ​​flame burning on the planet will destroy everything. It is useless to hide in water. Liquid water will be boiled, and the sky will also not work, because the heat of the flame will go upwards, if it is not equipped with collectors. The super-large-scale viewing angle and the ability to fly is far from enough to survive in the sea of ​​flames.

With this in mind, there is a reasonable explanation for the demise of animals.

"Yes, large areas of flames are disastrous whether they are animals or plants. I think animals are going to extinction in the sea of ​​flames that frequently appear."

After some simple thinking, other collectors also agreed with this idea of ​​the same race.

"What you said makes sense. If the environmental factor of the sea of ​​fire is added, the competition between animals and plants will no longer be about who is more subjectively active, but about whose vitality is more tenacious. Obviously, animals are at this point. It is far inferior to plants, so they are eliminated."

On this planet 100 to 150 million years ago, there used to be animals with simple structures that feed on plants. However, a certain plant on the planet has undergone mutations and evolved the ability to burn itself. As a result, plants have set off a scene. The fire, which forced their natural enemies to destruction-plants defeated animals.

In front of the flames, it is no longer the two races who are more powerful than the flames. The competition between them is the survival ability. Whoever has more births will grow and grow faster.

Obviously, on this planet, plants have completely abused animals in these aspects.