Buzz
Insects are ubiquitous across the planet, representing the most diverse group of organisms known. With over 900,000 species identified and named, they make up about 80% of all discovered animal species. In terms of both numbers and biomass, insects dominate life on Earth in a way no other group can match.
It is believed that insects emerged approximately 480 million years ago, coinciding with the time plants began their transition to land. Since that moment, they have evolved into an astonishing array of forms with remarkable adaptations. Though their lack of internal skeletons leaves the fossil record incomplete, many ancient insect fossils have been found. Here are ten of the most captivating examples.
10. Butterfly Scales
Butterflies and moths, delicate as they are, glide through the air with wings dusted in tiny scales. These insects belong to the Lepidoptera order. The scales provide several benefits, with the most striking being their ability to scatter light and produce bright, colorful patterns. This effect is achieved through minuscule structures that diffract light on their surface.
Although butterfly scales are among the smallest parts of a butterfly, their fossilized remains represent the oldest known evidence of moths and butterflies. Dating back around 200 million years, these scales were discovered in a 10g sample of sediment excavated in Germany. From this single sample, which once rested at the bottom of a lagoon, researchers uncovered seven different species of Lepidoptera.
9. Lacewing Larvae
Amber provides the ideal preservation medium for ancient insects. When an insect becomes trapped in sticky sap, it may meet its end, but its preservation is practically guaranteed. As the sap hardens and undergoes chemical changes, it transforms into amber, perfectly encasing the insect's exterior in a time capsule.
Around one hundred million years ago, the predatory larvae of a lacewing fly met an unfortunate fate by becoming ensnared in sap. Modern lacewing larvae feed on soft prey, but these ancient larvae had long, sharp mouthparts, suggesting they targeted more challenging creatures that could potentially resist. The amber-preserved larvae also show significant differences from their present-day counterparts, implying that life during the Cretaceous period may have been far more dangerous.
8. Ancient Insect Camouflage
Numerous insects are exceptional at blending into their surroundings. This ability helps them evade predators or even avoid detection by their prey. Camouflage can take various forms, but one of the strangest methods involves insects wearing the bodies of other creatures to conceal themselves. For instance, assassin bug larvae collect the carcasses of ants and carry them on their backs.
This behavior of carrying debris has evolved independently across different insect species, and in some cases, it has been preserved in amber. One remarkable example is a lacewing larva, dating back over 100 million years, found with dismembered parts of other arthropods attached to its back. Another insect larva, called Hallucinochrysa diogenesi, was discovered with plant filaments draped over it. These behaviors necessitated several evolutionary changes to secure the debris, indicating that such forms of camouflage likely evolved much earlier than previously thought.
7. The Insect Alien
Amber deposits can sometimes yield insects so strange they resemble creatures from science fiction. One researcher found a fossilized insect that looked like an alien and even made a Halloween mask based on it. However, he had to remove the mask after it frightened trick-or-treaters too much when they visited his house.
The insect, believed to be about 100 million years old, was so unusual that scientists classified it under a completely unknown order of insects, named Aethiocarenodea. Discovering a new insect order is exceedingly rare because, despite nearly a million identified species, all insects fall within just 32 orders.
The newly discovered insect—Aethiocarenus burmanicus—features a triangular head, which is connected to its body by only a narrow attachment. This unique head structure would have allowed the insect to turn its head and view directly behind itself. Fossil evidence also suggests that it could produce a substance from one of its glands that repelled predators—much like how it repelled trick-or-treaters.
6. Insect with Bulging Eyes
Being able to look behind you by simply turning your head is impressive, but imagine having 360-degree vision all the time. To achieve this, an insect would need an extraordinary number of eyes or eyes that are oddly shaped and positioned. One such insect, trapped in amber, possessed eyes that protruded from its head like light bulbs, giving it continuous all-around vision.
Palaeotanyrhina exophthalma, whose name means 'outside eyes,' utilized its extensive vision to hunt prey. Once it located its target, it would move in and grab it with its modified front legs, which contained special glands that produced a sticky substance to trap its catch. Ironically, this expert hunter met its own sticky fate when it got caught in sap.
5. Insect Ears
Bats have been a major force in shaping the evolution of insects. Many species of bats prey on flying insects, triggering an ongoing evolutionary battle between the two. Insects have developed strategies to evade bats, while bats have honed techniques to catch them. It was once believed that butterflies evolved from moths that ceased flying at night to escape bat predation, around 50 million years ago. Furthermore, it was thought that many insects developed acute hearing to detect the bats' echolocation. However, recent evidence suggests that neither of these assumptions is true.
Fossil evidence dating back to the time before bats evolved reveals that certain insect species already possessed a highly developed sense of hearing. Well-preserved fossils of crickets and katydids from around 50 million years ago display the same auditory organs found behind the knees of their modern counterparts, indicating that their ability to hear evolved long before bats emerged.
The evolution of hearing in insects is a complex story, with at least 17 different instances of its development throughout history. This variety arises from the diverse strategies various insect groups have adopted to detect sound.
4. The 'Frankenstein' Insect
The past is a foreign land; they have different customs there. Even the insects of the past behaved in ways quite unlike today. Modern mayflies are known for their peculiar life cycle, spending most of their lives as larvae and emerging as adults only for a brief period of hours or days. During this fleeting phase, their sole purpose is to mate and reproduce—they don’t even eat. However, fossils of early mayfly relatives suggest that their way of life wasn’t always so brief and one-track-minded.
These ancient insects, known as Coxoplectoptera, lived about 120 million years ago. They have been likened to Frankenstein's monster due to their unusual combination of features, which had never been seen together in a single species before. Their wings resembled those of a dragonfly, with a vein pattern similar to that of a mayfly, while their front legs resembled those of a praying mantis. Unlike modern mayflies, their adult form actively hunted and consumed food, suggesting they led a very different lifestyle.
3. Insect in Opal
Opals are some of the most stunning gemstones on Earth, their vivid colors shimmering with movement. Yet one of the most extraordinary opal finds wasn’t just about the play of light—it was a fossilized insect within the stone.
This discovery seems almost too improbable, as opal typically forms from silica spheres settling in water, a process not conducive to the fossilization of insects. Yet, a fossilized insect was found in opal from Java, dating back approximately six million years. Remarkably, the insect's open jaws, antennae, and fine hairs are clearly visible. Many theories have been suggested to explain how this fossil came to be, but despite the uniqueness of the find, its authenticity is still a subject of debate.
Following the discovery of the first insect in opal, a second specimen was found at the same site in Java. Whatever the circumstances of its fossilization, it seems there may be even more beautifully preserved insects within opals, awaiting excavation.
2. The Oldest Insect Fossil
In the 1920s, a fossil was unearthed in Scotland, dating back approximately 400 million years. Although it was tiny and only a fragment of the whole organism, early microscope technology offered limited insight. At the time, the fossil was believed to possibly relate to insects in some way. In 2004, the specimen was revisited, and researchers were astonished to find that it closely resembled modern insects.
The fossil of Rhyniognatha hirsti consists mainly of the creature’s mouthparts. Its triangular mandibles strongly resemble those of today’s flying insects. Though no flying insect fossils have been discovered from before 325 million years ago, this specimen suggests that the evolution of flight may have occurred much earlier than previously believed.
Sadly, the fossil was preserved in a hot spring, making it unlikely that a complete specimen, with intact wings, will ever be found. It turns out that throwing your samples into a boiling pond is not the best way to preserve them.
1. Pollen-Carrying Insects
When we think of insects pollinating plants, the image of cheerful bees fluttering between flowers often comes to mind. However, flowers themselves only began to evolve around 140 million years ago, while evidence of insects carrying pollen dates back a remarkable 280 million years.
Before the evolution of flowers, plants reproduced through pollen for millions of years, with the wind mostly handling its spread. Insects may have lent a hand, though. Fossils of a species known as tillyardembiids reveal that six of these insects had pollen stuck to their bodies, heads, and legs. It is believed they fed on the pollen found in the cones of conifers.
The pollen was from a limited number of species, suggesting that these insects were specialized feeders. Although it can't be definitively proven that these insects pollinated the plants they visited, it's a reasonable assumption that, at least occasionally, they transferred pollen from one plant to another, aiding in plant reproduction.
