Twenty-seven, kill the rooster! Chickens are our common poultry and naturally belong to birds, but you know that in paleontological research, chickens are also a branch of dinosaurs, called ornithosaurs. Dragon and phoenix are symbols of auspiciousness in traditional Chinese culture. The phoenix is a legendary bird from ancient times; the dragon is an auspicious reptile that combines the characteristics of various animals. After the Western word Dinosaur (dinosaur) was introduced into China, it was integrated with traditional culture, and the reptiles that dominated the land in the Mesozoic era were naturally translated as "dinosaurs".
Through scientists' continuous discoveries about biological evolution, it has been proven that the dinosaur "dragon" and the phoenix "bird" are actually inextricably linked - fusion! The best proof is the abundant discovery of bird-winged dinosaurs.
Figure 1. Ecological restoration map of the strange Fujian dragon. (Image source: Wikipedia)
01How come dinosaurs have "bird wings"?
In the vast land of China, dinosaur fossils have been unearthed in almost every province, such as Mamenchisaurus in Sichuan, Qingdaosaurus in Shandong, Lufengosaurus in Yunnan, etc. Even the stegosaur Mangkansaurus is found on the Qinghai-Tibet Plateau, which makes Fujian, where no dinosaurs have been discovered, a special case. However, in recent years, major breakthroughs have finally been made in Fujian Province, and a more complete and rich dinosaur puzzle has been put together, allowing people to have a more comprehensive understanding of the ecology, distribution, and evolution of dinosaurs.
The first dragon in Fujian Province, which broke through the previous record of no dinosaur fossils in the province, was published in September last year and was even featured in Nature magazine, attracting much attention from the academic community.The dinosaur was named Bizarre Fujianosaurus (Fujianvenatorprodigiosus), not only is it the latest Jurassic period in time, but also is theJurassicThe most "south"Avialae dinosaurs fill the gap in the early evolution and distribution of birdsImportant key links.
As mentioned earlier, the strange Fujianosaurus is the most "southern" ornithopteran dinosaur, but what are ornithopteran dinosaurs?
Generally speaking, when talking about dinosaurs, classic dinosaur images such as Tyrannosaurus Rex, Triceratops, and Brachiosaurus will come to everyone's mind. Because these tall and majestic images are so different from birds, although Archaeopteryx was discovered as early as 1861, the view that birds originated from dinosaurs was still "non-mainstream" until the 1970s. Later, with the discovery of a large number of feathered dinosaurs in the famous Jehol Biota in western Liaoning, a series of evolutionary processes from dragons to birds were completely established.
Figure 2. Sinosauropteryx (Sinosauroopteryx) is the first feathered non-avian theropod dinosaur discovered in the Jehol Biota. (Drawing: Bob Nicholls, Image source: Wikipedia)
According to the most commonly used cladistics in current biological classification, a taxonomic unit should include the most recent common ancestor and all descendants of all organisms in the phylum.To put it simply, to treat you and your brothers and sisters as a family, you have to trace your roots back to your parents and all your children, so that you can be considered a complete family.. As the descendants of theropod dinosaurs, birds naturally belong to the dinosaur family. Otherwise, deliberately excluding birds would be as unnatural as deliberately excluding a nephew or niece when talking about our own family.
Although this approach is in line with the laws of nature, it will cause a lot of inconvenience in people's communication. In particular, the evolution of birds towards flight is too unique. If we have to consider the situation of birds every time we discuss dinosaurs, there will be too many exceptions. In order to facilitate everyone's communication,Generally, when talking about dinosaurs, an "unnatural" classification that does not include birds is set, called "non-aviandinosaur";Excluding non-avian dinosaurs and including the branch of birds, they are called ornithomorphs., or what we call "bird wings" here.
02 Ornithosaurus ≈ Birds?
It sounds like "ornithopods" are equivalent to "birds". This answer is actually correct or incorrect, depending on how to define and understand birds.
It seems that it is not difficult for us to identify a bird now, but evolution is a continuous and gradual process. As we continue to trace our ancestors, the boundaries of classification gradually blur. We can see some dinosaurs that look very much like birds, with tails, claws or teeth. To prevent scientists from communicating with each other in different ways, clear classifications must be defined.
Figure 3. The fossil of Archeopteryx shows many features that are different from modern birds, such as teeth, claws on the forelimbs and tail. (Image source: Wikipedia)
Under this classification,The birds we usually talk about refer to "Neornithes" in a narrow sense, that is, the origins of all birds dating back to modern times.most recent common ancestorand all descendants, excluding Archaeopteryx, Confuciusornis, Enantiornithes and other species that differentiated earlier.. The broader term is what we call "avianida" here. The classification is based on a branch that is closer to birds in morphology and appearance, but different from the closely related Deinonychus (to put it more strictly, it is a group that is more closely related to other feathered non-avian dinosaurs and living birds).
After scientists conducted a series of analyses, they found thatFujianosaurus and Anchiornis (Arcniornis), Xiao Tinglong (Xiaotingia) and so on are more closely related, so they are classified together into the early branch of Ornithidae..
Figure 4. The taxonomic relationship between Fujianosaurus and Ornithosaurus. The branches from top to bottom are Anthopterygium, Enantiornithes, Confucius Birds, Jeholornis, Archaeopteryx, Eochinosaurus, Dawnbird, Xiaotingsaurus, Anchiornis, and Fujianosaurus. (Image source: Reference [1])
03 The mystery of time and space between dinosaurs and birds
The earliest records of birds in the past mainly come from Archaeopteryx. This creature from the late Jurassic period about 150 million years ago has a very "bird" appearance, especially its wings and feathers, which has led to a large number of gaps in the study of the evolution from dinosaurs to birds.
After the discovery of a large number of feathered dinosaurs in the Jehol Biota, these deficiencies in morphological evolution were gradually made up. However, these creatures all came from the early Cretaceous period, so it is still difficult to make up for the lack of earlier fossils. As scientists continue to explore, finallyFound in Northeast ChinaAbout 160 million yearsBefore, the Yanliao biota from the middle and late Jurassic.
Many magical animals have been discovered in the Yanliao Biota, including Yiqi, a bat-like creature that used wing membranes to fly. This proves that before dinosaurs used feathers and wings to fly into the blue sky, or at about the same time, they briefly tried to use wing membranes to take off. The miraculous discoveries of the Yanliao biota don’t stop there;Many specimens of early bird-winged dinosaurs were discovered, filling the gap in the past where no related transitional species could be found in strata older than Archaeopteryx..
Figure 5. Restored picture of Akipteryx. It can be seen that this dinosaur is different from the wings and feathers of birds. It flies with wing membranes (drawn by Emily Willoughby, picture source: Wikipedia).
Anchiornis is a good example. This bird-winged dinosaur was originally thought to be a type of troodontosaur when it was discovered, which means that it has many characteristics close to dinosaurs. andAnchiornis also had feathers on its hind limbs, similar to MicroraptorSuch a four-wing structure, these appearance features are well connected with the process of dinosaurs flying into the blue sky and turning into birds.. also,Anchiornis also has melanosomes found in feather fossils,yesThe first method is to determine the different distribution of hair color on the whole body.Dinosaurfossil, in addition to the black body and black and white wing feathers, there is also a brown-red crown.
Figure 6. Restoration map of Anchiornis (Drawing: Reference [2])
04The most "southern"JurassicBird-winged dinosaur
recently discoveredFujianosaurus dates from the latest Jurassic period about 148 to 150 million years ago.Except for the German Archeopteryx,Filled the Yanliao biota about 160 million years ago to the early Cretaceousbird fossil discoveryThe 30 million year blank. In addition, early bird-winged dinosaurs in the past were concentrated in northern areas such as the Yanliao Biota and Solokhoven in Germany (where Archaeopteryx was discovered). This "southern" discovery of the Jurassic also makes up for this shortcoming, proving that these early bird-winged dinosaurs had a wider geographical distribution.
Figure 7. Fossils of Fujianosaurus (picture source: Reference [1])
In addition to these important meanings in time and space, the biggest feature of the Fujian dragon's appearance is itshind legs,haverelativelyShorter thighs, longer calves and soles of feet. This ratio is generallyRun fastanimals appear; in modern birds, andWaterside wading birds such as egretsnear. Therefore, researchers identifiedThis dinosaur either had scuds or lived near water, both of which let us know that early bird-winged dinosaurs had more diverse life forms.
In addition to Fujianosaurus, there are also a large number of reptile fossils found in this fossil site, including aquatic or semi-aquatic turtles, soft-shell turtles, and crocodile-like linoosaurs. Through these rich fossils, the researchers named the site "Zhenghe Fauna" and can look forward to more and richer discoveries in the future.
Figure 8. The stratigraphy of Zhenghe fauna is the cluster of fossils found (Picture source: Reference [1])
05 Today’s Dinosaur World
Through the study of ornithopteran dinosaurs, we can better understand the origin of today's birds, and it also makes us realize that we are still in an era when dinosaurs are around us, and we even eat them. For example, the duck meat, eggs, and foie gras on the table are all part of the ornithopteran dinosaurs in terms of classification.
This year is the Year of the Dragon, so I specially selected an article about bird-winged dinosaur paleontology that is a combination of dragon and phoenix to dedicate to you. I wish you all good luck after reading the article, may the dragon and phoenix bring good fortune, good luck and wealth, and all the best!
References:
1.Xu,Liming;Wang,Min;Chen,Runsheng;Dong,Liping;Lin,Min;Xu,Xing;Tang,Jianrong;You,Hailu;Zhou,Guowu;Wang,Linchang;He,Wenxing;Li, Yujuan;Zhang,Chi;Zhou,Zhonghe(2023-09-06)."AnewavialantheropodfromanemergingJurassicterrestrialfauna".Nature.621(7978):336–343.
2.Li,Q.;Gao,K.-Q.;Vinther,J.;Shawkey,M.D.;Clarke,J.A.;d'Alba,L.;Meng,Q.;Briggs,D.E.G.;Pr um,R.O.(2010)."Plumagecolorpatternsofanextinctdinosaur"(PDF).Science.327(5971):1369–1372.
Author: Liao Junqi, Ph.D. from Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, visiting scholar at Yale University
Review: Pei Rui, Associate Researcher, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences
Produced by: Popular Science China
Producer: China Science and Technology Press Co., Ltd., China Science and Technology (Beijing) Digital Media Co., Ltd.