Evidence that birds originated from archosaurs

Just when the clamor that birds originated from dinosaurs is overwhelming, my country's famous paleontologist and researcher Hou Lianhai of the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, has always insisted on the view that birds originated from archosaurs. Not long ago, the owner of this museum, Long Zi, paid a special visit to Mr. Hou Lianhai, asking him to talk carefully about why he insisted that birds did not originate from dinosaurs.

Mr. Hou Lianhai took out a copy of the British "Nature" magazine, one of the world's most authoritative scientific journals, published on June 17, 1999, and pulled out the article he published on it titled "The Original Confucius Bird" "New Species and Its Double-Arched Skull", which introduced Longzi to his new discoveries and the evidence that birds originated from archosaurs.

Confucius bird

This article by Mr. Hou Lianhai describes a newly discovered group of Confucius birds. This new Confucius bird is named Confuciusornis ducheni. It is the most perfectly preserved Mesozoic bird fossil currently available. The discovery of Confuciusornis duovani solved the long-standing debate about the skull structure of Archeopteryx. That is, as the most primitive bird known in the world so far, both Archaeopteryx and Confuciusornis should have postorbital bones and squamosal bones on their skulls. These two primitive structures left over from their reptile ancestors are very different from later birds, especially modern birds. In addition, the double-arched skull of Confuciusornis ducheni proves that birds originated from the earliest type of double-arched skull in the reptile family - archosaurs, rather than dinosaurs. Dinosaurs, like birds, are descended from primitive archosaur reptiles. Of course, groups such as crocodiles and lizards also differentiated from archosaurs.

Mr. Hou Lianhai commented on the issue of the origin of birds that has been hotly discussed at home and abroad recently. He believes that judging from public opinion reports, it seems that the issue of the origin of birds has been solved, but this is actually a misunderstanding. The debate about the origin of birds that began more than 100 years ago has not stopped. In recent years, a series of major discoveries in western Liaoning, China have provided unprecedented new information for the debate on the origin of birds. In particular, the discovery of several "hairy dinosaurs" has made it easier for people to believe that birds originated from dinosaurs. Not long before the discovery of Confuciusornis duovani, associate researcher Xu Xing, a young dinosaur expert at the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, published the results of his study of the "accidental Beipiaoosaurus" belonging to the therizinosaur class, once again providing a new opportunity for birds. The hypothesis of originating from dinosaurs provides evidence; Xu Xing also cited a mandibular fossil of Slothosaurus found in Yunnan Province, indicating that birds differentiated from dinosaur groups earlier than the earliest known bird fossils so far. era. However, a closer look reveals that the situation is not that simple.

Chinese dragon bird

Primitive Archeopteryx

Accidental Beipiao Dragon

Liaoning bird

Archaeopteryx

Petite Liaoxi bird

If you pay attention, you will find that there are at least four kinds of "hairy dinosaurs" that have been considered by some scientists to be related to birds in the near future: Sinosaurus, Archeopteryx, Slothosaurus, and Accidental Beipiaoosaurus. Some time ago, the assertion that Sinosauropteryx was the ancestor of birds was widely speculated. Recently, Xu Xing and other scientists believe that therizinosaurs are the origin of birds. In fact, the four types of dinosaurs mentioned above are actually different types of dinosaurs belonging to four families. Their basic skeletal structures are very different from those of birds, but they have one common feature, that is, they all have velvet. Feather-like skin derivatives, so how can we conclude that birds originated from dinosaurs? The nature of the feather-like skin derivatives has not yet been fully determined, because they do not have rachis structures like the feathers of tail-feathered birds, and are more developed on the forelimbs and tail. Bird feathers are also a skin derivative, but their biochemical composition is completely different from that of reptile skin derivatives. Its protein component is a special kind of keratin.

On the other hand, judging from the members of the Confucius Bird biome that have been discovered, the hypothesis that birds originated from dinosaurs is also problematic. In this community, in addition to Confuciusornis, there are also Liaoningornis, Eoantiornis and Petite Liaoxibird. Liaoningornis is recognized as the ancestral type of living birds. The petite Liaoningornis is only 10 centimeters in size, making it much smaller than other ancient birds. It's hard to imagine that such diverse primitive birds all originated from dinosaurs at the same time.

Researcher Hou Lianhai’s views are echoed by some scientists in the international academic community. Professor Feduccia, a famous American ornithologist, wrote an article and believed that some of the characteristics of birds are close to an archosaur named Magalancosaurus that was discovered in Italy during the late Triassic period. Therefore, he believes that birds originated from Archosaurs; Professor Walker, a British paleontologist, wrote in a letter to researcher Hou Lianhai and listed many characteristics of Confuciusornis as being very close to an archosaur called Silphinosuosaurus from the late Triassic in South Africa. , so she also believed that birds originated from archosaurs.

animal tags：