Sharks are cruel and cunning, they are terrified of beings in the ocean and the top killer among fish.
In fact, the shark family has a long history and is also very inspiring. Although they are always bullied by the overlords of the earth in history, they do not surrender and constantly strengthen themselves.
Shark: I don’t want to work hard
In the end, after its own efforts, the shark has survived batches of overlords over 400 million years.
As the saying goes, the ocean is the overlord of flowing water, and the iron-beaten shark.
Female shark
Four major families
Hydrama fish all over the world occupy half of the vertebrates on earth. These fish are mainly divided into two types: radial fin fish and cartilage fish .
has been poured forward for more than 400 million years, and the fish on the earth are divided into four major families , namely cartilage fish, radial fin fish, meat fin fish and shield skin fish .
cartilage fish, as the name suggests, most of their bones are soft. Although they also have a spine, the components of spine tend to be soft tissue .
So It is difficult for us to find the remains of shark , we can only find its teeth, because the teeth are the hardest part of the shark's body.
Shark is a cartilage fish . Strictly speaking, fish of the systomatum shark shaped order can be considered sharks. They are actually a very large group of .
sharks are all "cartilage"
There are 250 to 300 species of sharks in the world, occupies many ecological niches in the ocean, and sharks are not cold-resistant. Most of them are distributed in tropical and subtropical sea areas. Only a few live in cold areas, such as Greenland Shark .
Not all sharks have bloody mouths, The food of many sharks is beyond people's expectations , such as the bass shark, which is a filter feeding animal.
In addition to sharks, various rays are also cartilage fish .
Cartilage Fish Ray
Rayfin Fish, this is a very successful family, they also span various waters, and it is found in from sea water, salt water lakes, freshwater lakes, river , and even in puddles on the roadside .
There are more than 30,000 species of on the earth, and are the most prosperous vertebrate group. is almost everywhere in almost any corner of the earth, from the Arctic to the Antarctic .
All fish in the narrow sense are radiant fin fish
The group of meat fin fish is very interesting. You can say that it has fallen because there are only a few species of left in .
However, you can also say that the fin fish has the last laugh. all the terrestrial vertebrates are descendants of the fin fish .
The existing meat-finned fish - speartail
Shield skin fish, it is more miserable. The entire class of has all become extinct , but Shield skin fish has cross-generational significance in biological evolution.
Because The first vertebrate animal on earth, , is the shield-skinned fish, among which star ancient creature - Deng's fish .
The overlord of the first generation of overlords Deng's fish
The birth of shark
Although it is known as the four major families, it was bullied by the arthropods in the ocean in the early days and was swam around. marine arthropods was the overlord of the earth at that time.
Under this wave of pressure, shield skin fish chose to face the challenge. They evolved 's solid scale , allowing themselves 's defense to increase , and then strengthened the strength of the jaw and increased the bite force to increase .
upgraded its own equipment shield skin fish, which represents the first time vertebrates dominate the earth . Since then, every overlord of the earth has been vertebrates.
vertebrates' pride
Shield skin fish defeated marine arthropods and reached the top of the food chain. Not only did the arthropods become their food, but the remaining three fish families were not spared.
The pattern of the four major fish families has changed. shield skin fish dominates the ocean , and meat fin fish chooses to leave the ocean to stay in fresh water .
Radiated fin fish was still a marginal character at that time. It could not get into the eyes of the shield fish. It could only act as the underlying ecological niche in the ocean .
only cartilage fish, and chose . Although their names have the word "soft", their personalities are not soft at all.
Flesh fish: 李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李李�
The result is of course very miserable. Among the Shieldfish, there are top predator Deng's fish. The early sharks have not yet evolved too much equipment, so was caught by Shieldfish and beaten up .
The proud shark of the cartilage fish family, was defeated in the first war of the ultimate food chain .
Early Sharks
However, perhaps it was their tenacity that "touched" the earth . About 365 million years ago, the earth experienced the second mass extinction in history. is known in history as the end of the Devonian mass extinction .
This wave of extinction is that is getting colder globally, sea levels are falling, and sea water is deficient in oxygen , which is a nightmare for the Shield-skinned fish that is dedicated to enhancing combat power and defense. After
Devonian , Shield skin fish withdrew from the four major fish families and became fossils forever.
Although the shark was beaten up by the overlord, the cartilage fish family where it is successfully survived the Devonian and entered the next era.
"Shark"Mart"Non-shark
survivor
After the Devonian Permian, shark ushered in a wave of explosions . During this period, the oceans did not have shield fish, and power vacancy , and sharks quickly filled this vacancy.
shark's diversity also reached its peak at this time, with large shark represented by rotto shark .
However, rotto shark is not a qualified overlord . Although it can grow 7 to 14 meters, its food is mainly various ammonite .
The teeth of the rotating shark are different from ordinary sharks. It is growing on the oral side of . The main purpose is not to cut prey like a serrated rotor, but to to better take out the meat of the ammonite .
The weird-looking spiral shark
This way of eating is similar to our eating snail , and it suddenly lost its domineering spirit.
The spiral tooth shark was completely wiped out at the end of the Permian period, and the shark family successfully survived with only a few ethnic groups. However, the disaster did not end there.
The extinction of Permian made the ocean empty in an instant, and the land also entered the harsh Triassic , with drought and little rain.
A group of -footed creatures broke into the ocean . They are the ancestors of various marine reptiles . They will later evolve ichthyosaur , plesiosaur and other well-known paleobiology.
Shark: Who are you all!
These marine reptiles are actually the juniors of sharks. They are the descendants of , , among the four major fish families, . The fin fish was in fresh water, but the was not good enough and went ashore .
It's good to go ashore. The meat-finned fish discovered a new world, so they went deeper and deeper, and finally evolved into their feet.
In order to adapt to swimming, these marine reptiles degenerate their feet. combines the ferocity of terrestrial vertebrates and the flexibility of fish .
sharks faced this group of animals that had cheated. Although resisted, the effect was not very good. For example, the mouse shark can dominate some seas, but cannot dominate the entire ocean , and it does not have the style of its own big brother Deng's fish.
Shark unfortunately became a background board
What's more annoying is that From Jurassic to Cretaceous , many animals came to get a share. What's more, crocodile houses and lizard houses have all come to the sea. The key is that the lizard houses have made a fortune and evolved Mosasaur .
Even , a family of , which has always been a commoner, has evolved predators like Sword Shooting Fish .
The Mesozoic life of the shark is so frustrating. It’s weak, it’s not weak, but it’s not the strongest. There are always one or two animals that hinder sharks from becoming overlords. Anyway, it’s going around in circles, and overlords are not .
This Mesozoic ocean was finally terminated by an asteroid. The shark sent away fin dragon , mosaurus, and sea crocodile . The reptile in the ocean only sea turtle and sea snake , two families that cannot cause storms.
Shark: Teacher Cang, if you have something to say,
Mammals have come
The familiar extinction is gone, and although the shark family has also suffered heavy damage, it is easy to say that it is not extinct.
As a result, another group of long-legged ones came, and they had hair on their bodies. They came from another animal group mammal , called cetacean .
If the marine reptiles of were equipped to crush sharks , then cetaceans were the IQ crushing sharks .
whale was first heard by sharks, but they soon came to take revenge. They have evolved large predatory whales such as Dragon King Whale and Meili Liviathan Whale .
Shark: It's endless, right?
Shark has evolved megalodon with color. The teeth of this megalodon are not as useful as those of the spiral tooth. They replace them for life, and will fight cetaceans for the rest of their lives for the rest of their lives.
The teeth of cetaceans are not good. They retain the characteristics of mammals having only one tooth in their lifetime. Therefore, when fighting with sharks, pay extra attention to their teeth, which also leads to many whales eating only the liver of sharks.
However, cetaceans are only a branch under the Orion Hoof. has fewer species than sharks. In addition, it has experienced many small and medium-sized extinctions. Today's top marine predators are only orcas supporting . Most cetaceans do not have ferocious characteristics.
0 The strongest megalodon shark in the history of the shark family
But this does not affect the shark losing his overlord position again. The shark said, it's terrible! I feel tired and don’t love you! You humans won't understand!
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