From Wang Yang to Handan "Longhu Lake", it has "traveled" for hundreds of millions of years

　　"Someone found fossils of ancient creatures in Longhu Park!" A few days ago, a "tourist inadvertently found hundreds of millions of years ago in Longhu Park - horn stone fossils" news has not gone away, attracted the attention of the central, provincial and municipal media, but also let many citizens can not help but wonder: Why is there a fossil of marine life in Handan? Which ancient creatures have survived and bred in Handan? What was this land we live like before ancient times?

　　With these questions in mind, the reporter interviewed Zhao Qiaojing, a teacher at the School of Earth Sciences and Engineering of Hebei University of Engineering. Zhao Qiaojing has long been engaged in the teaching and research of paleontology and paleogeography, and she will tell you about "Handan you don't know".

　　Handan was once an ocean hundreds of millions of years ago

　　The reporter learned that the fossils found this time are preserved in the limestone of Longhu Park in Congtai District. According to the staff of the relevant units, the limestone where the fossils are located comes from Wu'an or Fengfeng and other places, and is a rock "native" of Handan.

　　"As can be seen from the images taken, these fossils are all Ordovician hornstone fossils, and it can be speculated that they are Amen horn stones." Zhao Qiaojing said that the picture can clearly see that the external form of the horn stone is straight cone-shaped, the shell surface has a significant ornamentation, and the characteristics of the fossil are straight shell, the next door is dense, the body tube is visible, and the body tube is large, located near the center, it is flat bead-shaped, and the neck of the next door is curved and short-necked, which is a typical feature of the Amen horn stone, so it is identified as Amen corner stone.

　　Zhao Qiaojing introduced that the hornstone belongs to the mollusk phylum and is a cephalopod with a hard shell. The ordovician-Silurian period of existence was the Ordovician-Silurian period, which was widely distributed in the Ordovician and lived in a normal shallow sea environment. "This also proves once again that our city of Handan was a vast ocean in ancient times." The Ordovicians, she said, between 490 million and 438 million years, have been 52 million years old. It can also be seen from the Paleogeographic Map of Chinese Ordovician Lithofacies that Handan belongs to the North China Stratigraphic Region in the Chinese Ordovician Stratigraphic Zoning Map, and the early Middle Ordovician period was a normal shallow sea environment, which is suitable for the survival of hornstones. In the late Ordovician period, due to the Taikang Movement (that is, some kind of crustal movement), the entire North China plateau rose to land, so it was no longer suitable for the survival of hornstones. "From these analyses, it can be seen that it is not surprising that there are horn fossils in Handan."

　　For the formation and discovery of hornstone fossils found in Longhu Park, Zhao Qiaojing has his own imagination: in Handan hundreds of millions of years ago, there was a group of hornstone creatures living in the shallow sea after death, which was quickly buried by sediments, and gradually, the soft part was decomposed, and the hard parts such as the shell were formed by a series of physical and chemical actions and fossilization, and the surface was exposed after the movement of the earth's crust. During the construction of Longhu Park, these limestones were transported from the western region of Handan to Longhu Park, waiting for the day when they were discovered...

　　Handan paleontological fossils are diverse

　　"In addition to hornstones, fossils of paleontology such as trilobites, brachiopods, gastropods, plitigmates, and ancient plants have also been found in Handan." Zhao Qiaojing said that the paleontological fossil resources in the Handan area are relatively rich, in addition to the Ordovician horn stones, there are also Cambrian, Carboniferous, Permian and other paleontological fossils.

　　She introduced that trilobites are an extinct class in the phylum arthropods, mainly living in normal shallow sea environments, because their dorsal carapace is divided into an axis leaf in the middle and two ribs on both sides of the two dorsal grooves to form a trilobite, so it is called trilobites.

　　"For arthropods, everyone is no stranger, it is a high-level invertebrate, such as shrimp, spiders, crabs, centipedes and so on. They are widely distributed and diverse, can live in a variety of waters, land and air, and are the largest phyla in the modern animal kingdom. It emerged from the early Cambrian period and has been breeding ever since. She said that the Cambrian period is 543 million to 490 million years old, which has experienced 53 million years, and the trilobite is an important fossil representative of the Cambrian, which is often used for stratigraphic grouping and sub-banding, so the Cambrian is also known as the age of the trilobite.

　　Brachiopods are marine solid benthic organisms, which have certain requirements for the nature, depth, salinity and so on of the seabed. For example, cave-dwelling tongue-shaped shellfish prefer sandy bottoms, fixed life brachiopods prefer rocky bottoms and seabeds with gravel and shells, and some brachiopods are distributed on the muddy seabed. "Through the differences in the living habits of different brachiopods, it is possible to infer the paleoenvironment very well." Zhao Qiaojing introduced that brachiopods began to appear from the Cambrian period and continued to modern times, but there are not many modern brachiopod species, all of which are marine, feeding on the larvae of seaweed and other animals.

　　She introduced that in addition to animal fossils, Handan also has many plant fossils. "As we all know, Handan is an important coal-producing area, and plants provide a rich material basis for the formation of coal." Coal is an organic bio-rock formed by biochemical action by submerging the remains of ancient plants into the water, then being covered by sediments and undergoing physicochemical and biochemical processes. ”

　　The discovery of paleontological fossils is of great significance

　　"Whether it is scientific research or mineral exploration, the discovery and identification of paleontological fossils play a very important role." Zhao Qiaojing said that not all organisms in the geological history period are likely to form fossils, because their preservation as fossils depends on certain conditions. First of all, their remains and relics must be buried, and secondly, they have not suffered fundamental damage during the long process of burial, so the paleontological fossils preserved in the long river of geological history are particularly precious.

　　"The discovery of paleontology also has important indicative significance for the search for mineral resources, and can be said to be the key to the discovery of underground treasure houses by humans." For example, she said, the shrimp box was named by the geologist Li Siguang, because of its short age of existence, only in the Carboniferous-Permian distribution, and the Carboniferous-Permian is an important coal-forming period in our country and even in the world, and the discovery of this organism has a very important guiding significance for the exploration and development of coal.

　　She also introduced that from the perspective of paleontological stratigraphy, fossils can also be used to determine the geological age of rocks, and different geological periods have different representative fossils. By studying the rock characteristics and biological fossil characteristics in the strata, it is also possible to analyze the sedimentary environment where the paleontology is located, analyze the environmental elements such as the distribution of sea and land, natural geography and its climate at that time, understand the environmental appearance of the geological history period, let human beings grasp the law of the evolution of the global environment, and predict the future evolution trend of the global environment. "To sum it up in one sentence: paleontological fossils can show us the history of the earth like a book, page by page."

　　In addition, paleontological fossils can also help humans understand the history of the survival, development and extinction of organisms at different times on the earth, and study the evolutionary laws of organisms on this basis, because the more ancient the organisms, the simpler and lower- Some beautiful paleontological fossils can also be made into handicrafts, which have certain collection and ornamental value.

　　Zhao Qiaojing finally said that for the public, the discovery of fossils can not only appreciate the style of paleontological fossils, learn the knowledge of paleontology from them, but also understand the history of the development of the earth, understand the relationship between human survival and development and natural resources, and guide everyone to rationally use natural resources and protect the geological environment.

　　Reporter Zhao Zhengjie