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10 Fascinating Facts About the Carboniferous Period

359 million years ago, one of the five major extinction events that shaped the Earth’s evolution hailed the end of the Devonian period in which life had started to colonize the land from the sea. The Late Devonian mass extinction hailed in the next geological period, the Carboniferous, which lasted from 354 to 290 million years ago, some 60 million years before the dinosaurs even came to be. The Carboniferous world was a remarkably different one to that we know today, but it is extremely significant nonetheless. The name Carboniferous is Latin for coal-bearing, which is appropriate given that much of the coal reserves we rely on today were formed during this time. Nonetheless, to today’s observer, the Carboniferous Earth would have looked and felt remarkably alien.

1. The Air Was Completely Different

The Carboniferous, as evidenced by air trapped in ice from that period, is known for having the highest percentage of oxygen in the atmosphere ever. If you were to visit the Carboniferous, you’d instantly notice that the air is richer’ to breath, since it was 32.5% oxygen as opposed to today’s 21% This dramatic difference also allowed insects to grow to truly ungodly pro portions, as you’ll find out later on.

2. It Was a Time of Enormous Climate Change

The early Carboniferous saw lush jungles and swamps span vast stretches of the world, and the average global temperature was some 6 °C warmer than it is today. The atmospheric CO2 content was also three times higher than preindustrial levels, making for an immense greenhouse effect. However, during the middle of the period, the glaciers started to advance from the poles and global temperatures decreased to bring about a severe ice age.

3. Timekeeping Wasn’t Easy

If you were to be transported back to the Carboniferous, your alarm clock and calendar wouldn’t be much use. 350 million years ago, the day was only 22.4 hours long, and there were approximately 385 days in a year. The Earth’s faster rotation, combined with its thicker atmosphere, also made winds significantly stronger than they are today.

4. The Map Was Unrecognizable

Since the Carboniferous was so long, the natural movement of the tectonic plates had ample time to change the map significantly, but at no time did it look anything like the one we’ re familiar with today. By the end of the period, what is now Africa, the Middle East, India, Australia and South America were all joined together with Antarctica. The Eurasian tectonic plate was connected to this enormous southern content, named Gondwana, by a thick strip of land.

5. Insects Ruled the Earth…

Long before dinosaurs, birds or mammals existed, insects ruled the Earth, leading the Carboniferous to be dubbed the Age of Insects. Due to the much higher oxygen levels, insects were able to evolve to horror movie sizes. The meganeura, for example, was a dragonfly sporting a 30-inch wingspan. Although not technically an insect, the arthropleura was another enormous creepy-crawly, a millipede that grew as long as a car. Adapted perfectly for the Carboniferous atmosphere, they would not be able to survive in today’s air.

6. …and Scorpions

Scorpions are one of the oldest orders animals on Earth, having existed for some 430 million years. However, the early Carboniferous saw the most horrifying scorpion of all -the 28-inch long pulmonoscorpius, the largest arachnid that ever lived. It’s likely that pulmonoscorpius lived on other arthropods and perhaps smaller amphibians.

7. Sharks Dominated the Seas

The early Carboniferous saw sharks at the top of the food chain in the seas, but they weren’t much like the sharks today. Among the stranger of the many species of that period was the akmonistion, characterized by its bizarre anvil-shaped crest and spines on the top of its head. Fortunately, however, at one metre (3 feet) long, it wasn’t particularly large. However, the helicoprion, which first appeared towards the very end of the Carboniferous, grew three times longer, and it also sported a circular saw blade for jaw.

8. Trilobites Started to Decline

Trilobites, a highly diverse class of marine arthropod, that ruled the Earth for hundreds of millions of years, started to decline rapidly towards the end of the
Carboniferous period, likely due to com petition with the explosion of versatile sea life. By the end ofthe period, only three families survived, which themselves became extinct some 250 million years ago.

9. Amphibians Were Highly Successful

Alongside insects, amphibians radiated to form the ancestors of the reptiles, birds and mammals that followed. These creatures made up the taxonomic clade of synapsida, which also includes all mammals. The earliest of these was the archaeothyris, a lizard-like creature that grew about 20 inches long and lived some 306 million years ago. The earliest synapsids also included the dimetrodons, a swamp-dwelling creature that evolved during the end of the Carboniferous.

10. The Carboniferous Was a Volatile Era

The Permian, which followed the Carboniferous, ended with the most severe extinction event in the Earth’s history, but it is now believed that this event was largely shaped things that happened long before. In addition to extreme climate change during the Carboniferous, large-scale volcanic activity and methane release from the sea beds may also have contributed to the mass extinctions later on that claimed around 95% of all species on Earth.

The Carboniferous ultimately ended with the Permian-Carboniferous Ice Age around 300 million years ago. Glaciers spread far and wide to cover some 50 degrees of latitude from the south pole. Oxygen levels also dropped, a trend that sealed the fate of all of the larger insect species. However, the world eventually recovered in the early Permian to bring in the birth of early mammals and many other lifeforms.