12 Giant Prehistoric Bugs We Are Glad Are Extinct

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There are many giant prehistoric bugs we are glad are extinct. These include giant bugs that were much larger than any bug we see today. In the content of this article, we will explore the biggest and worst bugs that roamed our earth millions of years ago.

Some of these bugs were as big as a human head, and they were often found in large numbers. Their primary use was to invade the nests of other insects and eat their young ones.

The prehistoric bugs that we are glad are extinct disappeared for a number of reasons. Global cooling, the evolution of mammals, and the asteroid that killed the dinosaurs all contributed to their extinction.

Let us find out more about these fascinating extinct creatures.

Why Were They So Big?

giant prehstoric bugs we are glad are extinct

Giant prehistoric bugs were able to evolve and grow to their massive sizes due to the increased oxygen content in the early Earth’s atmosphere. This allowed them to have a much higher metabolic rate, which in turn helped them grow larger.

Dinosaurs evolved approx around 230 million years ago and quickly cut down on the number of giant insects. The rise of the dinosaurs caused a mass extinction of bugs, which left behind only the largest and fittest. This is why we are glad they are extinct!

The decrease in oxygen levels was the main reason why these giant bugs went extinct. With less oxygen, their food sources dwindled, and they were no longer able to thrive. Consequently, this led to their ultimate extinction.

What are some giant prehistoric bugs we are glad are extinct?

Ladybug extreme closeup

Though giant prehistoric bugs were fascinating, we are grateful they are no longer around. The prehistoric bugs had sharp mandibles that they used to pierce their prey’s flesh and suck out the blood.

Additionally, many of them were as big as a human head! Thankfully, their extinction means that we no longer have to worry about them taking over our world.

A few of these giant prehistoric bugs are –

Meganeuropsis Permiana

Meganeuropsis Permiana was a large, prehistoric dragonfly that lived in the Carboniferous period. It had a wingspan of over two feet and is thought to have been one of the largest dragonflies to ever live.

This species of bug could grow to be 28 inches and 17 inches wide, making it one of the largest bugs to ever exist. Furthermore, these prehistoric bugs were up to 2 feet long and had a wingspan of over 3 feet! Thankfully, they are now extinct.

Manipulator Modificaputis

Manipulator modificaputis was a cockroach that lived during the Cenomanian period, which was approximately 100 million years ago. It is believed that they were about 5 inches long and had a wingspan of about 8 inches. They are thought to have been predators and scavengers.

It had long legs that scientists think it used to either chase prey or ambushed it. This fearsome creature was about the size of a small dog and had a long, sharp beak that it used to eat its prey.

The Manipulator Modificaputis was a giant prehistoric bug that could turn its head to look at you. It is believed to have been extinct 60 million years ago.

Monster Millipede

Sting of Heterometrus xanthopus, Sting, Venom, Lonand, Satara,  Maharashtra, India

Millipedes are a type of arthropod, which is a larger classification that includes insects. Arthropods have segmented bodies and jointed legs. Millipedes can be distinguished from insects by their lack of wings and antennae.

They used to come in a range of different sizes, from one foot to eight and one-half feet long. They varied in color, but most were brown or black. Millipedes had two pairs of legs per body segment, which is why they got their name (from the Latin word for “thousand”).

This prehistoric bug had a segmented body that could grow up to nine feet in length! Despite its size, this millipede was herbivorous and primarily ate decaying plant matter.

Supersized Scorpion

Jaekelopterus rhenaniae was a giant sea scorpion that lived about 390 million years ago during the Devonian period. It is considered to have been the largest arthropod that ever lived, measuring over 8 feet in length!

This creature was a cannibal, meaning it would have fed on other marine animals. It is thought that this creature would have been at the top of the underwater food chain due to its size and predatory behavior.

It is estimated to have been about 2.5 meters long, making it one of the largest arthropods to ever live. Despite its size, it was not very successful and went extinct around 380 million years ago.

Anomalocaris Canadensis

Anomalocaris Canadensis was a large, predatory arthropod that lived 490 million years ago. It had a large head with two large eyes and a long, segmented body. It was one of the top predators of its time and is considered one of the first true apex predators in Earth’s history.

It was a relative of arthropods, which are the largest and most diverse group of animals on Earth. This ancient creature used special limbs near the tip of its nose to snag prey and devour it with rings of sharp teeth.

Anomalocaris Canadensis was a large, three-to-six-foot-long creature that would be a problem for us today if it were still around.

It had a large, circular mouth with serrated teeth and could easily swallow prey whole. This prehistoric bug is one of the reasons we are glad they are extinct!


alamy bugs

Jaekelopterus was a large, extinct arthropod that is thought to have reached sizes up to 8 feet long. It is thought to be the largest prehistoric bug that ever lived, and we are certainly glad it is extinct!

It is thought to have a set of large pincers that it used to hunt down prey. Jaekelopterus is the largest known arthropod from this period and is considered to be an efficient apex predator.

It is believed to have weighed around 440 pounds. Scientists believe that Jaekelopterus was a highly efficient hunter that used its large claws and excellent eyesight to take down prey.


Arthropleura was a genus of millipede that lived during the Carboniferous period and reached lengths greater than 10 feet. This makes them one of the largest land invertebrates to ever live. They are extinct now, thankfully, but they were a formidable sight on the prehistoric Earth.

They were giant prehistoric bugs that scuttled around on rainforest floors like giant armored carpets. They were up to 2.5 meters long and weighed up to 45 kg! 

It was the largest land invertebrate of its time and could reach up to 2.5 meters in length! Despite its fearsome size and large mandibles, Arthropleura was herbivorous and subsisted off decaying vegetation on forest floors.


Megarachne was a genus of sea scorpions that lived about 300 million years ago. They were some of the largest and most fearsome creatures to ever live on Earth, measuring up to 2.5 meters in length.

It was identified as an extinct genus of spiders, which would have made it the largest known species of terrestrial spider. However, further research has since shown that Megarachne is not a spider at all but rather a myriapod (an arthropod with many legs).

Megarachne was first discovered in 2002 and was thought to be a giant prehistoric spider. However, further research showed that it actually was a kind of water-dwelling arthropod. It is now believed to have been up to 2 meters long and lived around 400 million years ago.

It had bladed limbs and is one of the many giant bugs that we are thankfully extinct. These creatures were horrifying and gave many people nightmares.

Titanomyrma Lubei

This ant species lived in Wyoming, and it was “monstrously big.” The ant, which was named Titanomyrma Lubei, was the size of hummingbirds and is thought to be a descendant of the prehistoric bugs that once roamed the Earth.

Titanomyrma Lubei is a prehistoric bug that lived during the Eocene epoch. It was discovered in 2012 by Dr. Lubei, and little is known about it aside from its wingspan, traits, and lifestyle.

What is extremely interesting about this species is that it may have been capable of powered flight, which would make it the largest flying insect to ever exist.

Paleoentomologists found that it most likely crossed an Arctic land bridge from Europe to America at a time when the Earth was warming.

This discovery of a giant prehistoric beetle is shedding light on how species can move across enormous distances. This new information could help researchers better understand the evolutionary history of beetles.

Mazothairos Enormis

arthropleura image

Mazothairos enormis was a large, prehistoric insect discovered in Illinois. It is the largest known species of praying mantis and is estimated to have been about 7 inches long.

Scientists were able to estimate the insect’s size and wingspan based on very fragmentary remains. This bug was as big as a human and had a wingspan of over two feet!

These bugs were the size of a small bird and possessed piercing, beak-like mouthparts that allowed them to suck plant fluids from plant tissues.

They were about the size of a modern-day crow and had wingspans of up to 3 feet. Scientists have found fossils of these creatures in China, and they are calling them “six-winged insects” because, in addition to their main wings, they sported tiny wings near their first pair of legs.

Mazothairos Enormis is a six-winged insect that was discovered in Thailand. It is the largest known prehistoric bug and is thought to have become extinct around 65 million years ago.

The insect has interesting physical features, including its six wings and two pairs of long antennae. It is not clear what the main function of the extra pair of wings was, but it is speculated that they may help with stability or navigation.

Apis Lithohermea

Paleoentomologists had found a mini-goldmine in Japan’s Iki Island archipelago. Its sedimentary rock formations, which developed under ancient lakes almost 16 million years ago, have produced a plethora of intriguing fossil insect fossils.

Among them is a now-extinct species of prehistoric honey bee that rivaled the size of the modern-day gigantic honey bee found throughout southern Asia.

Apis lithohermaea, a giant honey bee that existed during the Miocene epoch, was introduced to the world in 2006. Its remnants have only ever been discovered at Iki Island’s Chojabaru-Zaki, and it is the world’s first prehistoric gigantic honey bee.

It was most likely a vigorous flier in life, with forewings measuring 12 mm by 4.5 mm and an 18 mm body. Its scientific name is a combination of the Greek word for “stone” (lithos) and Hermes, the Greek god’s herald (counterpart of the Roman god Mercury).

The finding of an open-nesting “stone messenger” did, indeed, increase humanity’s knowledge of insect life during the mid-Miocene, notably addressing notions of the region having a warm temperature during this time period.

Ypresiosirex orthosemos

Most individuals are wise enough to avoid wasps in general, owing to their painful sting and intense territorial character. They normally grow to be about an inch long, which is large enough for people to notice (and avoid).

However, Ypresiosirex orthosemos, better known as the fossil horntail wood-wasp, which existed 53 million years ago, were a lot more dangerous than the present-day wasps.

Y. orthosemos was discovered in Canada and may grow to be 3 inches long. It resembled its modern-day equivalents, according to experts.

Experts concluded that Y. orthosemos thrived in habitats with similar conditions to today’s horntail wood-wasps.

In fact, the prehistoric wasp appeared to be attracted to the same types of trees and flowering plants as its modern counterparts, including hemlock, sequoia, cedar, maple, elm, and others.

Furthermore, while Y. orthosemos lived, the Earth’s temperature was mainly tropical, but the elevation location where the fossils were discovered would have been colder.

This corresponds to what entomologists know about today’s horntail wood-wasps, which prefer toastier environments with “acceptable” temperatures.


Now that you have the knowledge about the giant prehistoric bugs and how big and dangerous they were, we are sure that like, just like us, you would be glad about how today we have tiny bugs and these giant ones are extinct.

About the author

A biotechnologist by profession and a passionate pest researcher. I have been one of those people who used to run away from cockroaches and rats due to their pesky features, but then we all get that turn in life when we have to face something.