Everyone now knows that before the human memory began, the knowledge we currently had about life came from the markers and fossils of organisms in layered rocks.
We found that they were preserved on shale slate, limestone, sandstone, bones, shells, fibers, stems, fruits, footprints, scratches, etc., which, together with the earliest tidal wave marks and the earliest rain erosion, formed our memories.
It is through careful examination and observation of these rock records that the history of life on Earth is stitched together.
This is also a fact that almost everyone knows today.
The rocks were not neatly stacked layer by layer, they were folded, bent, pushed, twisted, and then mixed together, just like after a library had been looted and burned.
rock
It is the work of many people throughout their lives that allows them to be recorded in an orderly manner and to be read.
The entire compass of time, represented by the rock record, is now estimated at 1.6 billion years.
The earliest recorded rock, which geologists call ice rock, is because there is no trace of life on it.
Large areas of icy rocks are exposed in North America, and in the eyes of geographers, their thickness represents at least half of 1.6 billion years, or 800 million years, which is the length of the entire geological record.
Let's revisit this important fact.
Half the time since land and ocean were first distinguished on Earth has left us with traces of life.
Ice rocks
These rocks have traces of rain, traces of babbling water, but there is no trace of life.
Cambrian marine life includes jellyfish, soft-tongued snails (swimming snails), primitive sponges, brachiopods (small round shellfish), right-angle stones, trilobites (hoodeds), polyps (cyathus), moss penstones, trilobites (trilobites).
Then, when we start taking notes, signs of past life begin to appear and increase.
In world history, we find these traces of the past at a time that geologists call the Proterozoic.
The first signs of life are traces of relatively simple, humble things: small shells, plant insects with stems and flower-shaped heads, seaweed, marine worms, and the remains of crustaceans.
Earlier organisms have reptiles like plant lice, aphids and trilobites that can roll into balls.
trilobite
Later, after millions of years, some kind of sea scorpion appeared, and more powerful creatures began to move, which had never been seen in previous worlds.
All of these creatures are not huge in size.
The largest of them is the sea scorpion, which is about 9 feet long.
There was no sign of life on land at that time, no plants or animals.
There are also no fish or vertebrates on Earth.
From this period in Earth's history, all the plants and animals that were able to leave their mark were creatures of shallow seas and intertidal zones.
If we want to find flora and fauna parallel to the Rocks of the Lower Paleozoic On Earth today, we should do our best.
Sea scorpion
In addition to the size of the volume, we can take a drop of water through a rock pool or scum ditch and place it under the microscope for a closer look.
We will find that these small crustaceans, small shellfish, animals and algae bear striking resemblance to the huge, clumsy archetypes that were once the king of life on our planet.
At present, the idea in people's minds is that the rocks of the Lower Paleozoic era cannot give us any representative explanation of the origin of life on our planet.
Unless these creatures have bones, or other relatively hard parts, unless they have a shell, or have enough volume and weight to leave obvious footprints or other marks in the mud, it is impossible to leave a fossil imprint of their existence.
There are still thousands of small molluscs in today's world, and it is hard to imagine that they will leave any trace of examination for future geographers.
anthozoan
In the past world, there were also hundreds of millions of biological species that once lived and multiplied, flourished and disappeared without leaving any trace.
The warm shallow lakes and oceans we call inanimates may be filled with an infinite variety of inferior, jam-like, boneless, shellless creatures, and many green, scum-like plants may already be all over the sun-exposed, intertidal rocks and beaches.
The record of the rock is merely a complete record of past life, just as a bank is a complete record of the people who exist around it.
It can only be recorded if a species begins to secrete shells, or bone needles, or carapaces, or lime branches, or something that can be provided for future records.
But before those rocks that carry any traces of fossils, graphite is sometimes found, a type of carbon that is in a state of separation, which some experts believe may have been isolated from a series of combinations through the very exuberant activity of some unknown organism.
If you like this article, please pay attention to @Idealist History Officer