How many of you know that there was a period when insects used to be extremely massive? It gets difficult for us to overlook one tiny insect on a day-to-day basis, but imagine encountering an eight-foot-long Arthropleura millipede, or a scorpion the size of a bicycle. That sounds quite scary. Humans, fortunately, were not alive to witness this spectacle back when this happened. The period I am referring to is called the Carboniferous period. According to scientists, multiple insect families were developed during that particular era. Numerous insect species grew to incredible sizes. It’s difficult for scientists to determine why we do not have them in similar sizes in this day and age.
Earth was saturated with oxygen approximately 300 years ago. We do not have similar levels of oxygen on earth at the moment; there’s only 21% oxygen, while the Carboniferous period had an atmosphere that had over 35% oxygen. A massive difference, I believe. Due to excess oxygen, insects of the Carboniferous period could support massive bodies. Being massive is a good thing when you are on your own in the wild as the resources are scarce; you can fight and hunt in a better way.
It is widely believed that Earth didn’t have trees before the Carboniferous period. Moreover, the trees of that particular era had massive ferns with shallow roots. They grew throughout the swamps that covered most of the planet during the Carboniferous period. Certain studies suggest that the lycophyte trees were over 98 feet tall and had trunks of 6.5 feet in diameter. We can say that the Earth was more like a massive, wild forest during that era; a forest with thousands of deadly insects.
The biggest of the lot; Meganeura
As I have stated before, the insects turned massive due to excess oxygen during the Carboniferous period. However, there was one insect that was considered the biggest predator of that time. Yes, I am talking about a dragonfly called the Meganeura. The prehistoric dragonflies were not pleasant-looking or nice in any way or form.
The fossils of Meganeura were discovered in 1880 in Stephanian Coal Measures. Please know that they are approximately 300 million years old. Meganeura is considered as one of the largest known insects that ever lived, with a reconstructed wing length of 330 millimetres, an estimated wingspan of up to 710 millimetres, and a body length from head to tail of almost 430 millimetres.
Why aren’t insects massive in this day and age?
The insects began to shrink down about 150 million years ago. Nobody knows why, though. However, certain studies suggest that the birds started showing up on planet Earth and that somehow made insects shrink in size. Another change appeared almost 260 million years ago; fungi and microbial life evolved to digest wood. The trees that had not been turned into coal were instantly digested, and their carbon was released back into the atmosphere. This somehow levelled out the balance of carbon to oxygen in the air.