According to the evolutionary view, all terrestrial creatures and amphibians evolved from fish. In the order in which species appear on Earth, this view does make a lot of sense.
When the earth was born, changed and stabilized, the image of the earth was a large water ball, and the earth was a vast ocean, and the earliest life was born in the sea.
After several land-making activities, the continents on Earth have a certain scale, and the creatures in the sea have long flourished. Plants also appeared on land, preparing for the arrival of land animals.
Crawling from the sea to land, this part of the organism is the earliest amphibian, which is not very mature compared to today's amphibians. Compared to fish, they evolved lungs and had a more advanced respiratory system. Limbs have evolved to help them walk on land and in shallow water.
The fishstone salamander is the first amphibian to climb from the sea to the land, and from this point of view, the fishstone salamander is the ancestor of all terrestrial creatures and amphibians on the earth today.
The image of the fish stone salamander is similar to that of today's lizards and salamanders, and in the late Devonian period, attempts from shallow water to land began. From aquatic to terrestrial, from invertebrate to vertebrate, the emergence of the fishstone salamander is a huge advance in the history of biological evolution.
The body of the salamander is about a meter long, with a fish-like head and fin-like tail, strong forelimbs and less robust hindlimbs. Strong forelimbs can help them crawl on land, while less robust hindlimbs act like a pulp, helping them swim in water.
The emergence of the fishstone salamander can only be said to be an attempt by organisms from aquatic to terrestrial. Although we regard the salamander as an early amphibian, and the salamander can breathe with lungs, the body of this organism still retains many fish characteristics, and on the basis of the shape of the fish, it tries to change its own body structure to adapt to the development of the land.
On land, the lack of buoyancy of water has aggravated the gravitational effect of the Earth's gravity, so animals need a complete spine and strong limbs to support the entire body and drive the body to walk. Turning around on land is not as flexible as in the sea, so a flexible head is needed to observe the surrounding environment.
The skull of the fish and the shoulder straps of the forelimbs are fixed and connected together, and the shoulder straps of the fish stone salamander can already move freely, that is, in this way, there can be flexible limbs, and it also shows that the head of the fish stone salamander has been able to move freely.
But their spines did not change flexibly, and today's terrestrial creatures and amphibians, the spine can be bent and moved. The spine of the salamander is interlocked, which limits its vertical movement.
That is to say, the fish and stone salamander that came ashore at that time may still walk like a fish, gaining thrust by swinging the body and pushing its body and limbs to walk. Their strong front paws are responsible for supporting the body, dragging the body and tail.
Also, it's amazing how many toes the salamander have. Today's reptiles are basically five toes with front paws and four toes with hind paws. The front paws of the salamander have six toes and the hind paws have eight toes, which may also be an attempt in biological evolution, they have advanced so many toes to help walk, and gradually evolved the claws to be more conducive to walking for a long time.
Although in the late Devonian period, the fish stone salamander came ashore and transformed from aquatic animals to amphibians, from an evolutionary point of view this is a good thing and a progress. But the descendants of the salamander are considering whether to return to the water or continue to develop on land. Some returned to the water, but ushered in extinction; some continued to live amphibians, such as tailless; some insisted on developing on land, but due to the progress of the times, they were gradually eliminated.
In any case, the emergence of the fishstone salamander is a milestone in the process of biological evolution. From here, organisms on the Carboniferous land developed, reptiles began to evolve over the next few hundred million years, after which mammals appeared and the ecological circle on the land gradually became complete.
Biological evolution is a bold attempt to finally choose the most suitable for their own stay, not suitable for elimination. After repeated bold attempts, we can pass down the best and survive better.