About 100 million years ago, knowing that you might not be able to sing loudly, let alone disturb your dreams on a summer afternoon.
Recently, researchers from Nanjing Institute of Geology and Paleontology of Chinese Academy of Sciences (hereinafter referred to as Nanjing Institute of Paleontology) have collaborated with multinational scholars to analyze the anatomy of fossils and extant cicadas.The findings were published in Nature Communications on January 8.
"It's an interesting study, and it still seems to me a little bit of a "star-hunting" success.""In the study, David Emery, a professor at the University of Sydney, gave me current katydid cicadas that only exist in Australia for my research, and some of the 'big cows' that have often appeared in the article have become my collaborators.
Little is known about early evolution.
Cicadas are commonly known as insects that are more common in daily life, and their cries are quite characteristic, often appearing in the hot summer afternoon.
Jiang Hui introduced that the current cicada family includes two families: cicadas widely distributed in the world and katydid cicadas left in Australia.The earliest fossils of Cicadas were found in the Triassic (250 million to 200 million years ago). The Cicadas of Mesozoic (including Triassic, Jurassic and Cretaceous) were abundant.
At present, little is known about the early evolutionary history of cicadas, especially paleoecological habits.
Under the guidance of Wang Bo and Zhang Haichun of Nanjing Institute of Paleontology, Jiang Hui summarized and analyzed the fossil record of Cicadas of Mesozoic, and reviewed the anatomical structure of Cicadas and Cicadas.
The study found that the fossils of cicadas in the Mesozoic period included Cicadas, Cicadas and Cicadas.Some Mesozoic fossils previously placed in the family Cicadidae may be closer to modern cicadas in phylogenetic relationships.Based on this, the researchers hypothesized that the two lineages of modern cicadas and katydids had diverged at least in the Middle Jurassic.
Due to conservation problems, the classification of insect fossils usually depends on some of the morphological features preserved."We conducted morphospatial analysis of the local structures of adults and larvae of cicadas and found that highly specialized homologous structures in cicadas fossils may contain transitional features that were previously overlooked."And Jiang Hui said.
The phylogenetic relationship between fossil and modern cicadas was established in the early evolutionary history of fossil phylogeny and morphology and ecological habits.
Jiang Hui said: "Through a more detailed study of these transitional feature structures, we can more accurately understand the evolution of morphological features and help clarify the patterns of macroevolution in insects."”

The katydid cicadas do not sing.
Studies have found that sound signals are an important means of transmitting information to many animals.
"Modern cicadas are able to produce the loudest sound in insects, up to 120 decibels.Usually, male cicadas use developed eardrum muscles to pull the eardrums to bend them back and forth to produce sounds, and the abdomen acts as a resonator to further amplify these sounds.And Jiang Hui said.
However, although katydid cicadas have eardrums and eardrum muscles, they are not developed and lack resonance chambers, they do not make calls, but communicate by transmitting vibrating signals.Two distinct signaling mechanisms have led to speculation about the vocal structure and behavior evolution of cicadas.
Jiang Hui said: "Our study was the first to find eardrum structures in cicadas fossils, and this is also the first reported in the fossil record."It was found that eardrum structure exists in all cicadas, and that eardrum structure is preserved in both females and males, so eardrum structure represents an ancestral sign of cicadas.
Jiang and others have shown through fossil analysis that cicadas in the mid-Cretaceous period (about 100 million years ago) may not have sophisticated vocal and auditory organs, they cannot make loud sounds, and are more likely to communicate through the matrix.
It was found that the cicada larvae and cicadas molted fossils in the middle Cretaceous period, which is the earliest known fossil record of cicadas.Jiang Hui said: "They have similar forefoot to modern cicadas, sickle-shaped tibia and enlarged femoral joints to form a grip structure, indicating that they have strong soil excavation and transportation capabilities.”
"We found that the fossil larvae had significantly enlarged and enlarged anterior and posterior labial bases, with marked muscle marks on both sides, and long prickly suction mouthparts.Jiang Hui said that this is similar to the lip base and oral organ morphology of the cicadas, suggesting that they most likely have evolved strong sinus muscles that can overcome negative pressure and pierce plant xylem catheters to feed on xylem juice.
"A great international cooperation.
After receiving her Ph.D. from Nanjing Institute of Paleontology, Jiang Hui went abroad to do postdoctoral work, and she has been studying cicada fossil materials for many years.
"They lived hundreds of millions of years ago and have a very small chance of being preserved, and it's fortunate to be able to find these fossil materials and have the opportunity to study them."Jiang Hui told China Science Journal, "Studying these fossils gives me a sense of conversation with time, and it's wonderful to hear them tell stories and feel hundreds of millions of years ago."I hope to be able to tell more people about their past events and stories through research to show these lovely little guys.”
Jiang Hui believes that paleontology research is a very interesting thing.First, paleontology itself provides the opportunity to explore the rich history and evolution of ancient life on Earth, to study at such a long scale, and to feel and realize more macroscopic and microevolution than modern research.
In Jiang Hui's eyes, paleontological research can explore organic and inorganic substances in nature, can feel the beauty and magic of nature, and also provide an opportunity to understand things more fundamentally."In the course of research, we need to learn multidisciplinary knowledge, use advanced scientific instruments, and participate in a wide range of collaborations, and these processes themselves are constantly breaking through their own cognition and abilities.""I see a lot of domestic and foreign researchers are persistent, love and serious about their field, for knowledge exchange, sharing and help, but also make friends from different countries, colliding with scientific research sparks, which is also very interesting."”
Jiang Hui also encountered various difficulties in her research, and she found that if she found a way to break down the big problems into small ones, she could be overcome step by step.
In this study, for example, samples of current katydids found only in Australia were donated by David Emery, who Jiang met on a nature lover's website, which gave him a better understanding of the structure of existing katydids."There are only 1 genus and 2 species of current katydid cicadas, and the relevant research data are relatively few, and some specimens provided by David have solved the problem of my unclear larval form of current katydid cicadas."We also named a cicada fossil after David as a thank you.
"Our study, conducted by scholars from Poland, the United States, Australia, Germany, Myanmar and the Czech Republic, including modern cicada scholars, fossil cicada scholars, arthropod scholars,Jiang Hui told the China Science Journal, "Everyone can understand from different perspectives and perspectives.