“Souvenirs Entomologiques” Preserved in Stones

As the only national-level insect museum in China, the Museum collection includes insect fossils from 17 orders and hundreds of families, covering almost all insect fossil groups that have been discovered in China.

Many of these fossils have been exquisitely preserved, to the extent that the delicate wings of the green lacewings, the fine mouthpiece of the scorpion flies, and the patterns on the forewing sheath of the beetles are clearly visible. Even the ants’ bristles are vivid to observe under the microscope, providing a breathtaking view.

Some of these lifelike insect fossils differ greatly from the appearances of such modern insects, three-tailed mayflies (Ephemeropsis trisetalis) being several times larger than modern mayflies; while some others are almost identical to their descendants, such as the froghoppers and cockroaches that have almost no changes in their patterns and wing veins.

These precious insect fossils give us the opportunity to meet face-to-face with tiny creatures from the era of the dinosaurs. Behind these fossilized insects there are many hidden prehistoric “Souvenirs Entomologiques”, each as full of mystery as the next...

The name “scorpion fly” derives from the fact that the males have enlarged genitals that look similar to the stingers of scorpions. There are 500 species under three genera known in the world, with the majority found in the northern hemisphere, living in forests, canyons, or areas with dense vegetation. They are low in number and not commonly seen, preying on various insects or feeding on different types of mosses.

The head of this particular fossil is hook-billed in shape, which is a typical feature of the Mecoptera.

Through the study of these insect fossils, we can discover that some insects with seemingly simple structures survived for hundreds of millions of years without any change, and many of them have survived to modern times, still very similar to their modern descendants.

Among which, modern cockroaches, stink bugs, and froghoppers are almost exactly the same as their predecessors; even the patterns on the wings have not changed, showing how successfully they had evolved!

Cockroaches are one of the most primitive Pterygota, or winged insects, in existence and were earlier settlers on the Earth than dinosaurs. They have an extremely high-level of environmental adaptability and have survived several of the mass extinction events in geological history as well as many man-made disasters.

According to media reports, during World War II, the first insects to appear in the disaster area after the nuclear explosion in Japan were cockroaches. When comparing modern cockroaches to cockroaches of 165 million years ago, there has been almost no change in the morphological characteristics, which proves the perfection of their evolution.

However, some giant insects, such as the once very prolific three-tailed mayflies, have disappeared, even though there were so many of them at one time that you can see dozens of individual insects crowded on the same fossil.

This is probably due to the emergence of birds during the Jurassic period. At that time, giant insects were easy targets for birds, so they were gradually eliminated, while small, low-key insects won their survival. Some experts have calculated that modern insects can theoretically grow up to two to three times their normal size, based on the oxygen content of the atmosphere. In reality, however, there are very few giant insects.

Around 165 million years ago, prehistoric cicadas were found all over the Earth, but strangely, well-preserved fossils of prehistoric cicadas have only been found in China.

The bodies of cicadas decompose easily, while the wings are relatively easier to preserve. The wings of prehistoric cicadas had a wide span and often had a spotted pattern, whereby they are also called the “butterflies of the Mesozoic period”. Prehistoric cicadas went extinct in the middle of the Cretaceous period, subsequently followed by the end of the dinosaurs.

Many of the insect fossils in the horsefly (Tabanidae) family possess flower-visiting habits, providing unique material for the study on the origins of the angiosperms. Although fossils of the oldest angiosperms have not yet been found, the appearance of the anthophilous horseflies indicates the time and place of the appearance of angiosperms.

Fossils of the flower-visiting horseflies proved that the angiosperms had already existed in northeastern China in the Late Jurassic-Early Cretaceous period, pushing back the time of origin of the angiosperms by at least 20 million years.

Although there are numerous kinds of insects in nature, humans only understand and have information about a small number of them — all the more so when it comes to fossils. We are so lucky to encounter these short yet eternal living beings, to whom an hour is like a day, a day is like a month, a month is like a year, and a year is like a lifetime.

After gaining an understanding of the mysteries of their lives, we may be able to explore some of the more profound essences of life from these survival modes that extended over four hundred million years, and thus gain new revelations.