According to the "News Hyperlink" of the Voice of China of the Central Radio and Television Corporation, the journal "Nature" recently published in the form of a long article the latest research results of Zhang Zhiliang, a doctoral student under the guidance of Professor Zhang Zhifei of the Early Life Research Team of Northwest University, "Fossil Evidence Reveals the Cambrian Origin of the Moss Phylum", announcing the discovery of the earliest known fossil of bryozoan (moss moss) on the earth in Zhenba County, southern Shaanxi. This study is thought to have advanced the origin of mosses by at least 50 million years.
What are bryozoans? Why are bryozoans found in southern Shaanxi? What value will the study of bryozoans bring to us?
How did moss become an animal?
Bryozoans are called bryozoans because of their very similar appearance to bryophytes. The epidermis of the moss secretes the worm chamber, also known as the worm room, which is the containment room for individual moss insects. The worm chamber and the worm chamber can be connected to each other, and the contiguous moss insects are very similar in appearance to the bryophytes. Bryozoans are aquatic creatures and generally live in lakes or oceans.
The earliest restoration map of bryozoans (courtesy of Northwest University)
Individual bryozoans are extremely small, and the length of a single bryozoan is mostly about 1 mm. Although small, it has all the organs and the digestive tract system is also very complete, and the mouth, esophagus, gastrointestinal, anus and other tissues are readily available.
Bryozoans have a special reproductive mode, which can reproduce both asexually and sexually. In the way of asexual reproduction, bryozoans can quickly form communities, while larvae produced by sexual reproduction can be metamorphosed multiple times to adapt to changing environments.
Communities of bryozoites are highly adaptable to the environment. Zhang Zhifei, director, professor and doctoral supervisor of the Department of Geology at Northwest University, said that although bryophytes are low-level organisms, their communities are highly socialized. In the bryozoan community, different individuals work together, some individuals specialize in reproduction, some individuals undertake environmental cleanup work, and some lichen mosses specialize in defending against foreign attacks.
How were they discovered? Why is it in southern Shaanxi?
This time, the fossil of bryozoan was found in southern Shaanxi. Where are the lakes and oceans where mossy animals live? Zhang Zhifei introduced that 500 million years ago, the southern part of Shaanxi was a vast ocean. The formation of the fossil bryozoans found this time is the early formation of the Cambrian Period (the historical period around 540 million to 480 million years ago is called the Cambrian), and before that, there were no studies or reports showing the existence of bryozoans during the Cambrian period.
After the discovery of bryophyte fossils in this formation, Zhang Zhifei's team and visiting foreign experts reached an agreement after preliminary research that the fossils were very important and may involve the origin of the bryophyte phylum, and even how the phylum participated in the evolution of the early Earth's environment.
What is the ecological effect of moss animals so small?
Bryozoans are primitive, low-level organisms, but bryozoans play an important role in natural ecosystems.
Mosses are conquerors of harsh environments. The early oceans did not have higher flora and fauna to survive, and bryozoans, like pioneers, were involved in the changing development of the early marine environment. At the same time, in marine ecosystems, bryozoans are not only an important source of nutrients for fish, but also able to hand over pollutant particles or debris through their own feeding and active adsorption.
The study of such paleontology can not only trace the origin of animal life and decipher the mysteries of biodiversity, but also provide a key basis for the comparison of international strata and determine whether the strata of different countries belong to the same period.
Research into ancient marine life such as bryophytes continues. Zhang Zhifei said that the next step is to explore the historical evolution process from the Cambrian period to the Ordovician period by studying bryozoic animals. Zhang Zhifei summed up his research as "understanding the earth, deciphering life, taking history as a mirror, and looking forward to the future." Early microbes and algae played an important role in the evolution of the earth, and he believes that only understanding the past and present lives of the earth can provide a basis for subsequent development.
Producer: Liang Yue
Reporter: Hejia Fu Zhao
Editors: Peng Yuji, Pan Yuwei, Liu Fei