Dinosaurs are not all extinct and still on earth

I believe that everyone is no stranger to dinosaurs. After all, they were once the overlords of the earth. Usually, we all think that dinosaurs are ancient creatures that have long been extinct, and there are no dinosaurs alive on modern earth.

However, there is a point of view that the dinosaurs are not all extinct, they still live on the earth, and even can be seen everywhere around humans, why do you say that? Here's why: All birds on modern Earth are direct descendants of dinosaurs. Let's see what exactly happened.

Speaking of the origin of birds, we have to say "Archaeology". "Archaeology" was once considered to be the earliest bird on earth. Its first fossil sample was found in the Solenoid limestone in southern Germany in 1861. "Archaeology" not only has some bird characteristics (such as feathers, wings, wishbone, hind foot anti-toed type), but also has some dinosaur characteristics (such as long teeth on the jawbone, dinosaur-like hind limbs, The feet have three-toed long claws, a double-concave spine, and a long bony tail).

Therefore, it was suggested that birds should have originated from dinosaurs, and "Archaeology" is a transitional species between birds and dinosaurs, but because there are very few fossil samples of "Archaeology", and its distribution area is also very small, This statement is not universally accepted. In the following days, with the continuous increase of fossil samples, people gradually discovered that birds and dinosaurs have many very similar physiological characteristics.

For example, the various bones of dinosaurs and birds (such as neck bones, pubis, carpal bones, keels, etc.) have very similar features, and even some dinosaur bones are hollow structures like birds.

For example, birds have a special way of breathing - "double breathing". There are many air sacs composed of membranes in their body cavity. Using these air sacs, the lungs of birds can occur twice in each breathing activity. Gas exchange, which in turn greatly improves the breathing efficiency of birds. And fossil evidence suggests that many carnivorous dinosaurs also had complex cavities, much like the air sacs of birds.

Another example is that when female birds lay eggs, a special bone layer rich in calcium is created between the outer bone and the bone marrow of the bones of wings and hind limbs, which is called the "medulla bone". bone), which helps birds make eggshells when they lay their eggs.

In all known animals on modern Earth, the "medulla bone" is a unique bone layer in birds, and fossil evidence shows that the pother Tyrannosaurus and Lambeosaurus, as well as the sauropod Brontosaurus fossils There, are traces of "medulla bone", and since these dinosaurs evolved separately at a very early time, it can be speculated that dinosaurs generally made this special bone layer.

Despite this, the view that "birds originated from dinosaurs" is still not universally accepted, because, between birds and dinosaurs, there is still a very important link missing - feathers.

Feathers are a distinctive feature that distinguishes birds from other vertebrates. For many people, "feathers or not" can be said to be the decisive evidence for judging whether an animal is a bird, and the same is true in paleontology.

As mentioned above, the fossils of "Archaeology" are quite limited, and some people even pointed out that the so-called "feather marks" in "Archaeology" fossils are formed by the decay of collagen fibers, so I want to prove that birds really originated From dinosaurs, more and more detailed fossil evidence is needed. However, because the fragile feathers are extremely difficult to preserve in the process of fossil formation, related research work has not progressed.

In the mid-1990s, paleontology finally ushered in major progress: Chinese paleontologists opened a world-class treasure trove of paleontological groups in the northern Hebei and western Liaoning regions of China - Rhee Biology group and Anatolian iota.

A large number of feathered dinosaurs and early bird fossils have been found here, including species older than "Archaeology" (such as "Euro Chinese Thesaurus"), as well as modern birds than "Archaeology" species (such as "Chinese dragon bird", "Confucius bird"), thus providing strong evidence for the origin of birds.

With the deepening of research, "birds originated from dinosaurs" quickly became the mainstream view in the paleontological community. People extracted the cocoons from numerous fossil evidence and finally confirmed the evolutionary route of birds, which can be simply described as lizards Chlorophyll → Main dragon shape subclass → main dragon shape class → bird necked main dragon → dinosaur general order → saurian → pother order → and raptors → birding → birds.

In the 2010s, scientists conducted in-depth research on the genes of birds from the perspective of molecular biology, and then completely determined the "kinship" between birds and dinosaurs, and identified birds as "the only one on the modern earth." Dinosaurs", in other words, the dinosaurs are not all extinct, and some of them still live on the earth.

On modern earth, birds can be seen everywhere around humans, and some birds (such as chickens, ducks, and geese) have long been domesticated by humans and used as a source of meat and eggs. As a generation of overlords on the earth, after tens of millions of years, dinosaurs were put on the table by the new generation of overlords on the earth. I have to say that this is emotional.