An Ultimate Guide to Meganeura: The Giant Dragonfly (2024)

Leave a comment / By: Alice Guzman / Updated on: 24th September 2023

Meganeura Pictures

The Meganeura

Imagine enjoying an afternoon outdoors when a giant insect with a 70-centimeter wingspan flies toward you! Fascinating yet terrifying!

That insect would be Meganeura, except that it went extinct 299 million years ago, and it would definitely not disrupt your afternoon picnic today!

Meganeura is one of the world’s largest known insects, which evolved and lived during the Late Carboniferous, when our world’s oxygen levels were quite high.

This giant insect had four large wings, a long abdomen, and a spherical head.

It is typically compared to extant dragonflies due to the resemblance between the two in terms of appearance, predatory specializations, and lifestyle.

However, Meganeura was a griffinfly, not a dragonfly.

Are you curious enough to continue reading? We encourage you to do so, as we’ve prepared quite a comprehensive handbook on Meganeura!

Physical Characteristics

Meganeura is a prehistoric version of extinct damselflies and dragonflies.

However, considering its wingspan reached 65–70 centimeters (25.6–27.6 inches), we can safely assume it was much larger.

Some scientists consider Meganeura to be one of the world’s largest flying insects!

One insect that may have been larger than Meganeura is Meganeuropsis, another griffinfly, which had a body length of 43 centimeters (17 inches) and a wingspan of 71 centimeters (28 inches).

Nevertheless, not all members of their group were so large.

Megatypus, for example, had a wing length of only 19.5 centimeters (7.7 inches), meaning that the wingspan was approximately 40–45 centimeters (15.8–17.7 inches).

The weight of Meganeura specimens with a wingspan over 70 centimeters (27.6 inches) was estimated at 100–150 grams (3.5–5.3 ounces).

These large insects had four wings, with the forewings being slightly longer and slenderer.

They probably had spherical heads equipped with large mandibles.

In insects, mandibles are two appendages protruding forward from near their mouths.

These mandibles are used to grasp or crush food or defend themselves against predators.

Meganeura’s mandibles were probably serrated.

Furthermore, scientists assume these insects had a large thorax and a long, slender abdomen.

The legs may have been spiny and robust.

Although often compared to dragonflies, Meganeura is not part of the Anisoptera infraorder of dragonflies.

Instead, it is classified as a griffinfly due to several distinctive characteristics.

First, Meganeura did not exhibit pterostigma.

In easier terms, their wings did not have thickened or colored features that stood out.

Secondly, their wing pattern was much simpler than that of dragonflies.

Some sources also mention that all Meganeura had appendages at the end of their abdomen, whereas these appendages have been observed only in male dragonflies.

However, their presence in both male and female Meganeura hasn’t been fully confirmed yet.

Habitat and Distribution

Meganeura fossils aren’t very common, so limiting this insect’s distribution to the locations where fossils were unearthed can be slightly misleading.

After all, we’ll never know how far they traveled!

However, based on the fact that its fossils were discovered in Commentry, France, and Bolsover, England, we can assume that Meganeura was an inhabitant of the modern-day European continent.

These insects existed during the late Carboniferous.

They were part of our planet’s ecosystems for approximately 6 million years, from 305 to 299 million years ago.

During the Carboniferous, our planet experienced active mountain-building processes.

By the end of the period, part of Europe was covered in a shallow epicontinental sea, so Meganeura may have flown above the waters, although we do not know how much it could fly before needing a break.

Since Meganeura appeared 305 million years ago, we may assume that their diversification occurred with the onset of the Carboniferous Rainforest Collapse, a minor extinction event that led to the fragmentation of rainforests and major climate changes.

As such, Meganeura probably lived in cool and dry habitats dominated by true coniferous trees like Walchia, which thrived in drier ecosystems.

Some scientists argue that Meganeura lived in open habitats and stayed close to water sources.

Since it’s believed that young Meganeura developed in the water, this possibility cannot be ruled out.

One essential thing to mention about the environment that served as home to Meganeura and other giant insects is that the oxygen levels were higher than today.

Behavior and Diet

Meganeura was a predator and likely fed on other insects.

Considering its size, it’s not a surprise!

Paleontologists suggest that Meganeura and other giant meganeurids led a lifestyle similar to that of hawkers, also called darners.

Their group includes the largest dragonflies that spend much time in the air, flying tirelessly.

They can fly both backward and forward, keeping the wings extended horizontally.

Hawkers are also known to have keen eyesight, which they use to catch prey.

Additionally, both dragonflies and meganeurids had specialized spines on their legs used to trap prey mid-flight.

While the adults feed on insects, the larvae are known to be aquatic predators.

Although they feed on insects as well, the young supplement their diet with small fish.

These dietary preferences may have been valid for Meganeura, too, except that the adults probably fed on small amphibians and other invertebrates as well.

Apart from this, little else is known about Meganeura’s daily habits and routine.

Life Cycle

To understand the life cycle and reproductive system of Meganeura, we must turn to what is known about extant insects and hope that few details have changed during the past millennia.

Most insects are oviparous, which means they reproduce by laying eggs.

Females have a pair of ovaries consisting of multiple ovarioles, otherwise known as egg tubes.

Males have one or two testicl*s where sperm is stored.

During mating, males rely on an aedeagus to deliver the sperm.

The female reproductive system can produce various substances used to protect the eggs as well as maintain and transport the sperm.

Some of these substances also serve to produce something called an ootheca, an egg capsule that covers a batch of eggs.

Although most insects are oviparous, some are ovoviviparous, which means that the embryo develops while still within the mother, the egg is laid, and the young hatch immediately afterward.

Only a few insect species are viviparous, which means they give birth to live young.

However, since Meganeura is often compared to dragonflies, which are oviparous, we can assume their reproductive systems are similar.

Another interesting thing to mention is that Meganeura may have used its abdomen appendages (if they indeed possessed them) during mating, similar to the mating behavior observed in dragonflies.

After hatching, insects are known to undergo metamorphosis, which is of two types and characteristic of different species: incomplete and complete metamorphosis.

The incomplete metamorphosis implies that the insects molt when they outgrow their exoskeletons.

Those who are still undergoing multiple molts are called nymphs.

While they’re quite similar to adults, their wings are still undeveloped.

The complete metamorphosis implies four developmental stages: the egg, the larva, the pupa, and the adult.

In short, this is how butterflies develop.

Considering that dragonflies undergo incomplete metamorphosis, we can assume that’s how Meganeura developed.

Scientists believe that insects like Meganeura spent much of their young lives in water and gradually switched to a terrestrial lifestyle as they matured.

Evolution and History

The oldest known insects date from the Early Devonian, roughly 420 million years ago.

At the time, they were wingless and, therefore, flightless.

Only during the mid-Carboniferous did they diversify and evolve into flying insects.

Approximately 328-234 million years ago, insects experienced rapid diversification, eventually giving rise to beetles, flies, moths, and wasps.

As you’ve probably guessed, the rapid diversification during the Carboniferous peaked when the insects reached an enormous size.

It is believed that this gigantism can be linked to oxygen availability.

More precisely, the oxygen levels at the time were above modern-day oxygen levels.

Studies show that the size of an insect is dependent on oxygen levels, as those living in high-oxygen environments are known to evolve larger than those living in low-oxygen environments.

Since today’s oxygen levels are lower than during the Carboniferous, it’s no wonder no giant insects survived.

Another reason why insects like Meganeura reached gigantism can be linked to a lack of predators.

Technical details aside, let us turn to when Meganeura was discovered.

This story takes us back to France in 1880.

The first Meganeura fossils were recovered from Commentry, a commune in central France.

Five years later, Charles Brongniart named and described the genus.

A century later, paleontologists unearthed another specimen in Bolsover, Derbyshire, England.

Interactions with Other Species

During the Late Carboniferous, our planet was dominated by arthropods.

One of the most renowned is Arthropleura, a giant millipede reaching a length of 2.5 meters (feet).

However, Meganeura and Arthropleura likely did not cross paths often.

First, the giant millipede was fully terrestrial, whereas Meganeura spent much of its time mid-flight.

Second, Arthropleura was probably a herbivore, so it did not compete with Meganeura for food.

Third, although Meganeura fed on invertebrates, Arthropleura probably wasn’t a preferred prey, considering how large it was.

Another dominant group of the Late Carboniferous is that of amphibians, some of which were also giants, reaching several meters long.

If young Meganeura developed in water, they may have experienced a certain degree of interaction with other marine invertebrates like brachiopods, echinoderms, annelids, trilobites, and corals.

Fish were abundant as well.

Other insects that existed during the Carboniferous included members of the Syntonopterodea, Palaeodictyopteroidea, Protorthoptera, and Dictyoptera groups.

Many of these are relatives or ancestors of modern-day insects.

Since Meganeura fed on other insects, we cannot rule out the possibility that it went for any of the above.

Cultural Significance

The gigantism of Meganeura has aroused the interest of numerous paleontologists and other field-related scientists concerned primarily with the reason these insects reached their large size.

Besides this, its discovery brought essential information about the Carboniferous period, its creatures, habitats, and ecological niches.

In the end, each discovered prehistoric creature represents a missing piece of our world’s evolutionary history.

The genus is well-known to wildlife enthusiasts as well.

After all, who isn’t interested in learning about a half-meter-long insect?

If you want to see a life-sized Meganeura specimen, we recommend visiting the National Museum of Natural History in Paris.

Its ancient collection includes the holotype specimen used to describe the Meganeura genus.

Surprisingly, Meganeura is a popular appearance in the media as well, having been featured in more productions than some dinosaurs!

Here’s where you can observe it:

• Walking with Monsters
• Prehistoric Park
• Earth: The Making of Planet
• Giant Monsters
• Jurassic Park III: Park Builder
• Jurassic Park Amiga
• Dinosaur Train
• Primeval New World

In short, Meganeura has become a prehistoric celebrity!

Conclusion

Meganeura was a giant prehistoric insect whose fossils were unearthed in France and England.

Although commonly called a giant dragonfly, Meganeura was, in fact, a griffinfly, a member of the Meganisoptera order.

Often called the world’s largest discovered insect, Meganeura reached a wingspan of 70 centimeters (27.6 inches).

It had four-veined wings and a long, slender abdomen.

Its spherical head was equipped with serrated mandibles used to catch prey.

Additionally, Meganeura may have had spines on its legs, which were helpful during mid-flight hunting.

It is believed that Meganeura grew so large due to high oxygen levels in the Carboniferous environment.

The same period served as home for other animals that have evolved to gigantism, like Arthropleura, so, for the time being, their size was a normal phenomenon.

Sources:

• https://en.wikipedia.org/wiki/Meganeura
• https://journals.biologists.com/jeb/article/221/19/jeb185405/33814/The-engineering-of-the-giant-dragonflies-of-the
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6092361/
• https://en.wikipedia.org/wiki/Dragonfly
• https://eweb.furman.edu/~wworthen/bio440/evolweb/carboniferous/mega.htm
• https://royalsocietypublishing.org/doi/10.1098/rspb.2010.0001#:~:text=However%2C%20a%20variety%20of%20recent,proportional%20investment%20in%20the%20tracheal

About The Author