<h1 class= "pgc-h-arrow-right" > extinctions of species on land and sea</h1>
In general, the extinction of species has its own rules, that is, starting from the top of the food chain, then spreading to the middle layer, and then the weak creatures at the bottom, such as lizards and frogs at the bottom, are the easiest to live. The more organisms that stand at the top of the food chain pyramid, the sooner they become extinct.
This is mainly for terrestrial ecosystems, as evidenced by the five mass extinctions on Earth, but differently for marine ecosystems.
< h1 class= "pgc-h-arrow-right" > top predators survive</h1>
As early as 13,000 years ago, there were many large creatures living on the earth, but the good times were not long, and due to the sudden change of climate, the ice age came again. The disaster wiped out giant carnivorous behemoths like saber-toothed tigers, as did animals such as mammoths, earth sloths, and llamas. These animals have dominated the earth for 100,000 years, because of the sudden climate change to extinction, but frogs, mole rats, money rats and so on have survived the disaster.
Interestingly, the situation in the ocean is different. In the Jurassic era, the Shanglong was arguably one of the most successful predators at the top of the ecological pyramid, and if the law of terrestrial extinction, the Shanglong should have become extinct long ago. However, in fact, the Upper Dragon has escaped many disasters, such as the disaster of the Jurassic transition to the Cretaceous period, the extinction event of the middle Cretaceous Period, and the Upper Dragon has survived the disaster, which is enough to prove that the extinction of terrestrial and marine organisms is not the same.
<h1 class= "pgc-h-arrow-right" > the decline of a generation of marine overlords</h1>
In the Jurassic era, the ichthyosaur was once the king of a generation, and later with the appearance of the upper dragon, the ichthyosaur relegated to the second place. However, although the fierce role of Shanglong appeared, the ichthyosaur was still a predator at the top of the food chain at that time. After years of development, Ichthyosaurs are not only rich in species, but also numerous in number.
However, at the end of the Jurassic period, ichthyosaurs began to decline, and many ichthyosaurs disappeared into the long river of history. Almost all members of the Ichthyosaurs were extinct, but only some of the slower-evolving Ichthyosaurs, which retained their original characteristics, survived.
<h1 class= "pgc-h-arrow-right" > the last Greek member of these ichthyosaur families, the flat-fined dragon</h1>
This ichthyosaur had sharp teeth and a strong mouth, and they belonged to the same species, the flat-fined dragon. It is a marine reptile with a flattened front fin. Although the reputation of the flat-finned dragon is not very loud, they have survived on the earth for 46 million years, which can be said to be the longest surviving ichthyosaur.
This ichthyosaur evolved almost exactly the same as the fish, with a flattened front fin with 8-10 finger columns, and the posterior fin is still evolving, constantly getting smaller. The curvature of the caudal vertebrae is obvious, the downward bend is close to 40 degrees, it is half-moon-shaped, and the caudal fin is extremely developed, capable of erupting a huge thrust in a short period of time. Biologists have calculated that its swimming speed can reach 40 kilometers per hour.
Computer resiliency diagram
<h1 class = "pgc-h-arrow-right" > body structure for swimming</h1>
And its vertebrae are short and inverted, the beak is curved downwards, this structure is very conducive to swimming, in the ventilation without the entire head to surface, reducing the resistance of the flatfin dragon when swimming. In the long years, it is precisely by virtue of its excellent body structure, super environmental adaptability and continuous evolution that the flatfin dragon has been able to rival the crowd and launch a fierce survival struggle with plesiosaurs and shanglong.
Some biologists even blamed the extinction of the late Shanglong on the extinction of the flatfin dragon, they believe that when the Shanglong had competitors in the ocean, it would maintain a state of struggle and actively evolve, but when the competitors were extinct, the Shanglong had less external motivation and was eliminated by history.
<h1 class= "pgc-h-arrow-right" > actively evolved for survival</h1>
Scientists through research found that a large number of ichthyosaurs eventually to extinction and ichthyosaur feeding species related, the vast majority of ichthyosaurs only eat some mollusks, such as squid, etc., in the Triassic to Jurassic period, the number of marine plankton is decreasing, which also led to a decrease in the number of squid, and finally many ichthyosaurs do not have enough food and extinction.
In order to be able to adapt to the marine environment at that time, the flat-fined dragon changed its diet. Through the study of the fossils, scientists have found that they prey on sea turtles. Turtles are powerful and defensive, and biologists speculate that the flat-fined dragon may have taken advantage of the fact that the turtle had just laid its eggs and was in extreme exhaustion, suddenly bit its neck, and then dragged it to death and swallowed it.
< h1 class="pgc-h-arrow-right" > newly discovered ichthyosaurs</h1>
Because of its late discovery, it lived later than other ichthyosaurs, so it is considered to be the last ichthyosaur. However, in September 2006, a Canadian paleontologist, Coldway, announced the discovery of a new ichthyosaur fossil. Coldway and another biologist studied the fossil and found that it turned out to be a new ichthyosaur species.
Non-original image
It is a pregnant ichthyosaur, and two curled embryos can be seen through a microscope. The newly discovered ichthyosaur was named Lyssaurus. In fact, whether it is a flat-fined dragon or a lyrexosaur, in the marine ecosystem, they are not the kings who stand at the top, and after their extinction, it means that ichthyosaurs have completely withdrawn from the stage of history and become the clouds of the past.
<h1 class= "pgc-h-arrow-right" > the stronger it is, the longer it survives</h1>
Ichthyosaurs have gradually developed from one of the weakest marine creatures in the beginning to the most powerful ocean overlords, which have experienced many winds and waves, but have survived, not to mention that in the ocean, the more elite predators are more likely to be extinct. If the extinction of ichthyosaurs is caused by poor ecological environments, then marine organisms that stay in similar closed or closed environments are the most likely to become extinct, such as big-eyed ichthyosaurs.
And those at the top of the predators, such as the shanglong, its range of habitat is very wide, the entire ocean may be their hunting range, even if the environment is very bad, but as long as there is prey in the sea, the shanglong will not starve to death due to lack of food, and can survive the crisis. Only a catastrophe like a glacier or a comet-like impact on Earth can end top predators like Shanglong.
< h1 class="pgc-h-arrow-right" > summary</h1>
Today, the ichthyosaur has long since become a legend, and the upper dragon has also been extinct for some reason. It's hard to imagine how it feels when the last ichthyosaur is swimming in the ocean, will it be looking for its partner all over the ocean? Or is it to find a quiet place to wait for the referee of fate?
Or is it dying because of a lack of food? Or will they choose a tragic way of dying to indict fate? When the last ichthyosaur swims in the vast ocean, will its pace become slow, will its movements no longer be powerful... When it falls into the ocean, the legend of the ichthyosaur ends here.