Top 10 Ancient Insects

Suggested by SMS

At the very mention of the Jurassic period, images come to mind of mighty dinosaurs lumbering through the jungle-like forests while flying creatures, with the wingspan of a light aircraft, soar overhead. But rarely do we consider the other end of the spectrum, that is, the smallest creatures of ancient times.

It stands to reason that there would have been insects buzzing around the head of Tyrannosaurus Rex, antagonizing  the massive creature because it couldn’t reach them with its short fore limbs. By the nature of the carnivorous lifestyle, it is reasonable to expect that bugs would have found their way to the odd carcass. So rather than looking at the mammoth skeletons of … mammoths, let’s turn our attention to the top ten ancient insects to infest the planet counting from ten down to one.

10. Eobelinae

The Eobelinae were a family of beetles that are often described as “prehistoric weevils”. They were recognizable as having long bodies that were distinctively flat, but even more distinctive were the rostrum. This snout was longer than the head and the first part of the thorax combined making it notable in comparison to the length of the insect as a whole.

Being found in Central Asia, Brazil and Spain in the period between 100 and 161 million years ago, the Eobelinae died out during the early Cretaceous period having lived through the late Jurassic period. The reason for their extinction is unknown, but it is worth noting that their descendants are still common in parts of the Pacific, Australasia and South-East Asia, as well as South and Central America.

In addition to the rostrum, Eobelinae was also recognizable by the bulge in the forehead and the spurs on the tibia of its middle and hind legs. They lived on the wood and fruits of diseased or dying plants or on deadwood, with healthy plants less important as food.

Growing to an average length of six millimeters, these insects were able to survive predators and disease for over sixty million years and have earned themselves a place in the top ten.

9. Prodryas persephone

There is no indication that the world was a drab or dull place one hundred and thirty million years ago, but it must have brightened significantly with the coming of flowering plants. The angiosperms, as they are correctly named, brought with them the most colorful and delightful of the ancient insects, the butterfly.

Prodryas persephone was the earliest butterfly fossil discovered in North America and places the butterfly between forty and fifty million years ago. But even earlier fossils can trace the origins of the animals back to the Cretaceous period. These butterflies were closely linked with the angiosperms and, while not looking to start a chicken and egg argument, there is conjecture that the flowering plants were the product of the butterflies’ pollination efforts.

In appearance the fossilized butterfly is of little note, having a wing length of twenty-four and a half centimeters (1 inch). But the beauty of this insect is not in the size of the creature, but in the inherent fact that the process of pollination began and worked well to encourage the growth of flowering plants that would evolve into fruits and vegetables.

8. Rhyniognatha

Among the earliest ecosystems to be found on land, the Rhyniognatha occupies a special role. It is believed to have lived four hundred and thirty-four million years ago and is the oldest insect ever to be discovered.

The fossil of the Rhyniognatha was found in sandstone which is believed to be the product of extreme hot spring and geyser action. Silica dissolved in the boiling water was spewed out across a wide area and as the water cooled the silica crystalized. In doing so, it encased the ancient insect and formed a three dimensional cast that was hardened under millions of years of sedimentary pressure.

A particularly astounding feature of the Rhyniognatha is the fact that it had wings. This suggests that the earliest of all insects was engaged in flight which, until this discovery was made, wasn’t believed to have occurred for conservatively another seventy million years.

While there have been bigger and more spectacular insects throughout the history of the planet, the emergence of the Rhyniognatha is the beginning of insect life.

7. Archimylacris eggintoni – Cockroaches

Many perceptions of cockroaches exist, most regarding their indestructibility. So it is probably not surprising that the ancient specimen of cockroaches, Archimylacris eggintoni, is not remarkably different in size than its contemporary descendant.

Scuttling around the floor of Carboniferous forests from three hundred to three hundred and sixty million years ago, the Archimylacris eggintoni was between two and nine centimeters (¾ and 3½ inches) in length and up to four centimeters (1½ inches) in width. It’s believed to have had wings and therefore could probably fly, although the lack of limbs on the fossils discovered has made it difficult to be confident of these facts.

However, through computer modeling, it has been determined that the legs of the Archimylacris eggintoni had sticky structures called euplantulae. This made it possible for the insect to climb on smooth surfaces and allow them to lay their eggs well above ground level. Claws on the base of the leg also assisted in climbing rough surfaces, so it could safety up above predators.

Perhaps the most significant fact in discussing the cockroaches is the lack of change over the past three hundred million years. Where other species have grown bigger or smaller or moved from the sea to the land, Archimylacris eggintoni has barely changed anything but its name. Maybe that consistency is the basis of the indestructible cockroach fallacy.

6. Trigona Prisca – Bees

Bees are one of the most important contributors to their ecosystem as they assist with the pollination of flowering seed plants. This is not a new role. In fact, they have been participating in the evolution of these angiosperms since as far back as about ninety million years ago.

The fossils that have been studied from this time have been notable in that they have shown that the earliest bees had no stinger. The evolution of this defensive feature probably says something about the emergence of predators and the desire to protect the hive.

Remarkably, examinations of the oldest fossils of bees have shown them to be worker bees. The significance of this discovery is that a social order had already been established and the bees discovered were fulfilling a role for the good of the hive.

5. Palaeodictyopteroidea

The size and ferocity of creatures from the Carboniferous period make it reasonably understandable to expect that most of them were carnivorous. Even insects were carnivores, which is why the Palaeodictyopteroidea were a notable group. These were among the first, if not the first of the herbivore insects to come to light.

Equipped with a beak, these insects had a wing formation similar to a dragonfly or meganeura, although, across the broad range of the family, the wingspan could be between twenty and four hundred millimeters (¾ to 16 inches). The diversity of the grouping has led to it being a classification for up to fifty per cent of the insects of the Paleozoic era.

The beak formation of the mouth of the Palaeodictyopteroidea was made up of a number of intricate parts including a lower and upper jaw, a series of tubular arrangements of the throat and a “mouth-like” covering.

Described as a “leaf- hopper”, the Palaeodictyopteroidea was the ancestor of a range of tiny creatures that make up a huge proportion of the insect world today.

4. Katydid

A fossil is largely a physical representation of an organism from the past. Whether it is an imprint left in the rock after the original specimen has decayed and dissipated or a specimen preserved in amber, it is something to be viewed and subjected to hypothesis. So when a fossil carries with it a soundtrack, then it becomes something special, as in the case of the Katydid.

As a nocturnal ancestor to the common cricket or grasshopper, the one hundred and sixty-five million year old insect has a place in the development of the species. But through examination of the wings a row of serrated teeth, the file, was discovered on one wing and a scraper was observed on the other wing. When the file was drawn across the scraper it produced an effect similar to that of a guitar pick strumming the strings of the instrument.

So, by rubbing the wings together, the Katydid was able to create a sound that can even be reproduced today. The purpose of the sound could be many-fold, but researchers are most confident with the idea that it formed a significant part of a mating ritual.

With the romantic vision of a Jurassic insect serenading its new love in one of the first evidence-based theories of natural music, there may be great interest in wondering what that Katydid next.

3. Meganeura – Dragonfly

One of the more spectacular of ancient insects is the Meganeura, which was, in many respects, identical to its dragonfly descendant of today. The only major difference was that the Meganeura had a wingspan of up to seventy-five centimeters (30 inches) making it the largest flying insect ever recorded.

The Meganeura lived around three hundred million years ago in the Carboniferous forests. A carnivore, it fed on smaller flying insects, small amphibians and, of course, other Meganeura. The absence of any significant predators, especially as flying vertebrates were still some time away, is provided as one of or part of the theory for their exceptional size.

Another theory, or a contributing one, is the high level of oxygen in the atmosphere, which is related to many explanations of gigantism in creatures from around this time. This seems to have some basis as the evolution of the insects to their current size suggests that the larger structural demands on wings and legs would have been impossible to maintain with less oxygen-rich air and simply an enlarged version of the current circulatory system.

Evidence of a smaller, but still impressive, member of the same family, the Meganeuridae, was found in France. Although its wingspan only extended to forty-five centimeters (17 inches), it is still looked upon wistfully by the puny dragonflies of present day.

2. Arthropleura – Centipede

The higher level of oxygen in the atmosphere around three hundred million years ago led to the survival of some creatures that were many times bigger than their present day relatives. The arthropleura was a significant example of this growing to more than two meters (6.5 feet) in length. Such a size may not have been surprising if not for the fact that an arthropleura was an ancestor to the centipede.

The largest invertebrate known to man, the arthropleura was believed to have poor eyesight, but exceptional senses of touch and smell. This would explain their choice of habitat, the Carboniferous forests of North America and Britain.

One of the first plant eating animals, the arthropleura was carnivorous early in its life until its digestive system developed the ability to eat vegetable matter. Despite the many predators that it had, this giant insect was well protected by an almost armor like shell and strong jaws.

1. Pterygotid Eurypterid – Sea Scorpion

The scorpion of about four hundred million years ago was not the small and lethal bug that we find today under rocks. The ancestors of these fascinating and mildly dangerous creatures were found in the sea and probably found more easily than their modern day counterparts as they were estimated to be between two and two and a half meters (6 to 8 feet) in length.

With claws a little under half a meter (18 inches) long and an armor-like shell, these marine monsters had little to fear and hung about for around twenty-seven million years. Their only real predators were exceptionally big fish, which weren’t uncommon, and each other. In fact, their cannibalistic tendencies were probably their greatest danger and placed them at the top of an unusual food chain.

The size of the Sea Scorpion is often explained in terms of the higher level of oxygen in the atmosphere at this time and the lesser effect of gravity in water. As bigger fish become more of a problem, the theory stands that the sea scorpions grew tired of the endless battle for survival and began to find sanctuary ashore. Over time, the oxygen levels decreased and the larger, less efficient circulatory system of these giants, and many others of the same time, was unable to sustain the size of the creature. This led to the evolution of the more compact, but just as grumpy, relatives that we meet today.

Since the emergence of the first ecosystem insects have played a major role in the development of life. They have responded to changes in food sources, atmosphere and environment. Their adaptability has seen them shrink dramatically and even leave the sea to establish life on land. They were the first animals to fly.

Whether the first recorded insect is seen as the most significant, the largest scorpion ever known was the most important or the first butterfly was essential to our discovery of color, there can be no doubt that the most populace classification of animals on the planet demand consideration and respect.