Human history is at most 3 million years old, and paleontological fossils have become archives of natural history.
Yumen is located in the Northern Qilian region, which has a large amount of paleontological fossils buried in the geological period and a rich variety, and is one of the important areas for the reproduction of paleontology in China. Paleontological fossils have been found in the Paleozoic Ordovician 500 million years ago, the Silurian 440 million years ago, and the Mesozoic 135 million years ago. There are paleontological skulls, fish fossils, butterfly fossils, sea mussel fossils, bird fossils, etc. It is of great scientific significance for understanding the evolutionary history of the earth and the evolution of life.
The discovery of Yumen bird fossils once shocked the world and amazed the world, in the Gansu Geological Museum, Yumen exhibited 23 insects, three-tailed ephemerals, birds, turtle fossils, Gansu birds as a national treasure boutique town museum. In 2012, after the deliberation and approval of the National Paleontological Fossil Expert Committee and the "Catalogue of Paleontological Fossils under National Key Protection (First Batch)" published by the Ministry of Land and Resources, three types of paleontological fossils in Yumen, namely Qingtou Mountain Gansu Nose Dragon, Yumen Chinese Hunting Beast, and Yumen Gansu Bird, were identified as first-class key protection objects.
Chronology of geological chronology and biological history of Gansu
I. The Ordovician
The geological age of Gansu can be divided into Proterozoic (1.8 billion years---60 million years), Paleozoic (600 million years---225 million years), Mesozoic 225 million years ----70 million years), Cenozoic (70 million years---10,000 years). As early as the early and Middle Ordovicians (500 million years), the area of the South China biota was the Northern Qilian Mountains.
The Paleozoic Ordovician, between 500 million and 440 million years ago, was a period of widespread biological flourishing in Gansu's history. The area of the early and Middle Ordovician South China biota in Gansu is the Northern Qilian region. Such combinations are seen in the trilobites of the early Ordovician trilobite swarm in the Nanshan Yingou of Yumen City, Yumen City, such as the spiny tail worm, the phantom head worm, the Schumad worm, the small deputy beauty goddess worm, and the sticky shell worm in the western Zhejiang and Guizhou Sandu regions of China.
2. Shiruki
After the Ordovician was the Silurian (440-400 million years), when a strong crustal movement occurred in Gansu, the vicissitudes of the sea and the mulberry fields, and the change of sea and land. In addition to the small Dahlman trilobite, normal grating penstone, Oshi penstone, saw pen stone, needle-like single pen stone, curly curl pen stone, spiral pen stone and other species that are the same as Gulang and Tianzhu, there are also new species of Gansu Aoshi pen stone, Yumen Oshi pen stone (pictured), and there are also honeycomb corals and ancient nest corals in coelenterates near Yumen; wrist and foot animals ancient stone swallow, copperless shells, etc.
In the late Silurian period, the plitites declined, and the marine invertebrates that increased with it were corals, brachiopods, sea lily stems, and round algae. The most important event is that during this period, the first plants were produced on the ancient continent of Gansu, the naked fern plant, and the fossil production area was concentrated in two places, one was the area around Ma mane Mountain in Subei County, and the other was the Yumen Dry Gorge Coal Mine. Naked fern is a primitive vascular plant, the surface is smooth, there is no differentiation of roots, stems and leaves, and now the higher terrestrial plants in Gansu are its descendants, enriched in local areas, set in situ after death, and some large and medium-sized coal mines are formed after petrochemical action, and the Dry Gorge Coal Mine was formed during this period.
III. Permian
There are not many fossils from the Early Permian (270 million years), and grid-long shells have been found in Wuhua Mountain, Yumen.
In the Late Permian (230 million years), a number of paleovertebrate fossils were excavated in the Yumen City strata, which has very important academic research value. In the 1980s, a vertebrate fossil site was discovered near the Dashan Pass in Yumen City, and after several excavations, a number of amphibian and early reptile fossils were excavated. With the assistance of the National Natural Science Foundation of China. This fauna is another discovery of Late Permian vertebrates in China after Xinjiang and North China. The most typical representatives are the Polo lizard and the dinosaur.
Polo lizard. It is a very unique class of small reptiles. The material found in Yumen Dashan pass is a right maxilla with a complete dentition on which 10 exquisite teeth are preserved, and a complete right mandible, each with a length of 35 mm. This is the first discovery of the Polo lizard in China and has important stratigraphic and biogeographical significance.
Chinese hunting beast. In the paleozoology of Yumen Dashan Pass, there is a large skull fossil - dinosaur fossil, which is not only the earliest carnivorous dinosaur found in China, but also the first relatively complete dinosaur skull fossil in China. Researchers have identified it as the Yumen Chinese Hunting Beast, which is the lowest tetrapod fauna in China at present, and the discovery of the Chinese Hunting Beast (new genus) in Yumen has made western Gansu another important distribution area after Russia, Kazakhstan and South Africa.
The first giant crocodile. It is a primitive theropod with a large and heavy skull, which was first discovered in China and outside of Russia, and this discovery enriched the composition of the Dashankou fauna. This discovery further demonstrates the link between the Dashankou fauna and the Russian Second Belt fauna.
4. Mesozoic
1. Triassic Yumen Lake Pterodactyl
Pterodactyls were flying reptiles of the same era as dinosaurs, they were not dinosaurs, but distant relatives of dinosaurs and crocodiles. In China, 8 provinces have found pterosaur fossils, which is the Asian country with the largest number of pterosaur species. In the late 1980s and early 1990s, fossils of pterodactyl were found in Yumen, Gansu.
So far, there are 7 genera and 7 species of pterosaurs found and officially named in China, and 2 genera and 2 species have been found in Gansu, namely Qingyang Huanhe Pterodactyl and Yumen Lake Pterosaur, which is close to 30% of the national discovery. From this point of view, Gansu is one of the main living areas of this flying reptile.
2. Dry Gorge Coal Mine formed
The Mesozoic Era (225 million years --- 135 million years) early and middle period, is a coal-forming period, Yumen Dry Gorge Coal Mine was formed in this period, the coal seam sometimes contains "coal yellow", also called amber has the effect of calming the nerves, activating blood stasis, diuretic and lymphatic effect, and has been listed as a medicinal garden by successive generations of pharmacologists. Amber has also been unearthed at the Yumen Fire Burning Ditch site, varying in size. In prehistory, it was not only an ornament, but probably a sacred object used by prehistoric ancestors as a ceremonial activity. Amber has its own unique and wonderful features, it feels warm in the hand, it is transparent to the sun, it rubs on the hide, and it can absorb dust; it is easy to carve, it can be ignited, and when it is burned, it will emit a resin fragrance. Ancient ancestors thought it had magic and therefore might worship it as a holy relic.
3, Cretaceous: sensational jade gate bird
The Cretaceous period was the last epoch of the Mesozoic Era, dating back about 135 million years. The most important event of the Cretaceous period in Gansu was the discovery of bird fossils in Gansu in Yumen Changma. The Gansu Yumen Bird is a fossil bird discovered in 1982 and was the earliest bird in the continental strata at that time. This bird has a long toe segment with a short claw with a sharp flexor nodule, and is a bird adapted to aquatic life, and the Gansu Yumen bird has become the oldest known bird in the world to adapt to the aquatic living environment. As soon as this specimen was published, it attracted great attention from the academic community.
It is in the middle of the Xiagou Formation in the northwest of Shenjiawan Village, Yumen Changma Commune, a rare fossil skeleton of the left posterior lower limb of an early bird, with all the phalanges and claws, is linked together in a natural state, the era is the Early Cretaceous, and the excavation of rare Mesozoic bird skeleton fossils, large and complete crocodile fossils and dinosaur fossils only the size of lambs was excavated in China. This marks the earliest life of bird ancestors in our country.
As soon as this specimen was published, it attracted great attention from the world's academic circles, and people's attention has shifted from marine sedimentary Archaeopteryx to continental sedimentary birds, and the eyes of hope have gradually turned to China. Breaking the record of only German birds in the Jurassic for more than 100 years.
The fossils of Mesozoic birds excavated this time are as old as hundreds of millions of years old, but the patterns are still clearly visible and well preserved. Since the discovery of the first Archaeopteryx fossil in Germany in 1861, the origin of birds has become one of the most interesting topics in the biological community, and the academic community has debated endlessly, a very important reason is that very few Mesozoic bird fossils have been found. In 1984, Professor Hou Lianhai of the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences excavated the "Gansu Yumen Bird" in Yumen, Gansu Province, and the bird bone fossils excavated this time confirmed the academic conclusion that the "Gansu Yumen Bird" was the first Mesozoic bird fossil in China. This discovery provides new evidence that Yumen is known as the "home of paleontological fossils", and at the same time, it also provides new evidence for the biological community to study the origin of birds.
Gansu Yumen bird restoration picture
The Gansu Geological Museum exhibits Changma fossils
Plant fossils, Jade Gate, Cretaceous
Fifth, the new generation
In the Eocene, paleontological fossils in Gansu were relatively rare, and only angiosperm pollen was found near Yumen. 40 million years ago, the Oligocene began to be active again in the paleocene of Gansu, the variety of mammals increased, and plant fossils often coexisted with ancient animals. The fossils were first found near The City of Luoma, north of Yumen City, where there are two species of animals, the ore rat and the Gansu beast. Beasts are now known to be fossil animals endemic to Asia. A fossil turtle named Jiayuguan Gansu Turtle was also found in Yumen Xinmin Fort.
6. Yumen Silicified Wood Geopark
At present, the province has been approved to establish 22 geoparks, including 6 at the national level and 16 at the provincial level. In the introduction of geological relics and geoparks of Gansu Geological Museum, Yumen Silicified Wood Geopark was grandly introduced. In September 2005, the Provincial Land Department established a provincial geopark, located about 40 kilometers southeast of Yumen City, with an area of 37 square kilometers, and the main geological relics are concentrated contiguous silicified wood. The park is rich in Mesozoic fossils, of which silicified wood, fish, insects, bivalves, gastropods, mesozoans and leaf limbs are particularly abundant, which has important paleontological research value. Silicified wood belongs to the ancient pine cypress class, the texture is hard, the annual ring is clearly recognizable, and it has high ornamental value.