The most important discovery in Liaoning Province is the feathered dinosaur, which links the relationship between dinosaurs and birds and leads to more hypotheses about feathers and flight evolution. In 2007, Mark Norrell and others found a feather stem tumor in the ulna of the velociraptor, which was regarded as strong evidence that the velociraptor had large secondary flight feathers.
The fossil and egg nest of the egg stealing dragon, its forearm retracts like a bird. Although fossils have no feathers, it is very likely that individuals had feathers to isolate the heat of eggs and larvae before their death.
Smaller theropods may all have feathers, while new larger theropods may also have feathers, such as Tyrannosaurus Rex.
Many dinosaurs have been found to have feathers.
Ancient birds, such as Confucius birds, have many characteristics of dinosaurs, such as teeth in the mouth, claws on the fingers, and the double temporal skulls of the latter.
Archaeopteryx retains some characteristics of birds, such as wishbone, feathers, wings and some relative first toes. It also has some dinosaur characteristics, such as long talus ascending process, interdental plate, sciatic process, herringbone long tail and so on. Orstrom also found that Archaeopteryx was very similar to Chironomidae.
1, Archaeopteryx has typical dinosaur characteristics.
Archaeopteryx is the oldest known bird ancestor. /kloc-in the middle and late 9th century, scientists first discovered archaeopteryx fossils living about1500,000 years ago in limestone beds in Bavaria, Germany. In recent years, paleontologists have unearthed more archaeopteryx fossils, which partly proved that archaeopteryx had the closest genetic relationship with carnivorous theropods, and supported the theory that birds originated from dinosaurs. The unearthed fossils show that the feet of Archaeopteryx are very different from those of modern birds and closer to theropods dinosaurs. The most obvious feature is that its second toe can be overstretched, almost the same as the feet of dinosaurs such as Microraptor and Bird's Foot Dragon. In addition, the first toe of Archaeopteryx grows inward, unlike the toes of birds that extend outward, but some of them are similar to the thumb of human palm; Moreover, its jawbone grows radially in all directions, which has obvious genetic characteristics of theropod dinosaurs. Scientists say that these fossils not only show that birds originated from theropods, but also show that Archaeopteryx did not climb the toes of branches like modern birds, so it would not perch on branches. Archaeopteryx is not so much a bird as a theropod dinosaur such as Raptor and Deinonychus.
2. dinosaur eggs are very similar to bird eggs.
Like birds, dinosaurs were hatched by males.
4. Fossil sticky substances confirmed that dinosaurs and birds were homologous.
Dinosaurs will become smaller during the evolution of flight.
Scientists believe that before the ancestors of ancient birds flew into the sky, their bodies usually became smaller. This is an art restoration picture, showing the big black dragon unearthed in the South Gobi of Mongolia. This dinosaur is nearly 70 centimeters long, which shows that it was very small before it developed its flying ability. There have been two opposing hypotheses about the origin of bird flight in academic circles. One is said by Lu Yuan, and the other is said by Shu Yuan. The former thought that the flight of birds was inherited by their ancestor dinosaurs, and gradually took off in the process of running and jumping. The latter hypothesis holds that birds first glide with the help of the height of trees, and then gradually develop a unique ability to fly with wings. Both hypotheses of the origin of bird flight admit that the ancestors of birds had long tails, but their functions are not exactly the same. According to the hypothesis of the origin of the earth, they beat their forelimbs when running to increase the speed of their hind limbs running on the ground. In this process, the scales on their bodies gradually increase and lengthen, and in the process of running and jumping, the scales eventually develop into feathers.
6. The respiratory system of dinosaurs is similar to that of modern birds.
Dinosaurs can breathe like birds.
8. Some dinosaur fossils have traces of feathers.
According to the research and analysis of the forearm of a raptor unearthed in Mongolia from 65438 to 0998, scientists believe that this dinosaur has feathers. Later, scientists found a piece of amber in the west of France, and found seven well-preserved feathers in the dinosaur period 200 million years ago. These feathers have the characteristics of hairy fibers of carnivorous dinosaurs of biped and feathers of modern birds. Scientists believe that this means that this amber fills an important gap in how dinosaurs evolved into birds.
9. Archaeopteryx's toes are very similar to dinosaurs.