The Largest Bug to Ever Roam the Earth

The Largest Bug to Ever Roam the Earth

The Arthropleura

In 2018 in Northern England, a stunning 29.5-inch-long piece of a prehistoric invertebrate known as the Arthropleura. This discovery was the third fossil recovered from one of these creatures and, once dated, it was found to also be the oldest. These insects roamed the Earth approximately 326 million years ago and measured nearly 9 feet long. Upon analysis of the newly discovered fossil, scientists determined that the individual had most likely weighed upwards of 110lbs and measured approximately 8.8 feet in length. With these measurements, the Arthropleura earned itself the title of the largest known bug to ever roam the Earth.

How Did Such Large Insects Exist?

Currently, scientists are uncertain of the actual answer behind why this happens. However, there is a leading theory with significant evidence that garners the support of many modern scientists. This theory has to do with the oxygen in the atmosphere and the way that bugs breathe. Insects possess a series of holes along the length of their bodies known as spiracles that take oxygen into inner tubes called tracheoles. These tracheoles spread throughout the body, getting as small as a micron in size to diffuse oxygen on a cellular level throughout the insect. Dr. Jon Harrison, entomologist at Arizona State University states that this very phenomenon could be the limiting factor in the size of insects. The larger the insect, the longer the canals of tracheoles would have to be, making it substantially more difficult to properly disperse oxygen throughout the insect’s body. Today, the percentage of oxygen in our atmosphere is approximately 21%, which accounts for the smaller size of insects. However, in pre-history, this was mot the case. According to a series of studies conducted by geologists, in prehistoric eras the percentage of oxygen in Earth’s atmosphere was at least 32%. This would allowing large bugs to breathe with ease due to the plethora of oxygen in the atmosphere at the time.

Some of the Largest Insects Alive Today

Today, the largest insects in existence include the Giant Weta (11cm), the Goliath Beetle (12cm), and the Titan Beetle (16.5cm), to name a few. While each of these bugs are impressively large, they are still a far cry from their prehistoric ancestors. Thankfully, we don’t have to worry about infestations of nearly 9-foot-long insects today.

Citations

Cohen, L. (2021) Scientists confirm the biggest bug to ever exist – an ancient millipede “as big as a car”, CBS News. Available at: https://www.cbsnews.com/news/ancient-millipede-as-big-as-car-scientists/ (Accessed: January 14, 2022). Nelson, B. (2013) These Are the 10 Biggest Bugs in the World, Business Insider. Mother Nature Network. Available at: https://www.businessinsider.com/10-of-the-biggest-bugs-in-the-world-2013-12 (Accessed: January 2022). Painter, D. (N/A) Big Big Bugs, Arizona State University. Available at: https://askabiologist.asu.edu/explore/prehistoric-insects (Accessed: January 2022). The Largest Complete Insect Wing Ever Found (2007) Harvard Magazine. Available at: https://harvardmagazine.com/2007/11/dragonfly-html (Accessed: January 2022). Titan Beetle (2011) The Smithsonian Institute. Available at: https://www.si.edu/newsdesk/snapshot/titan-beetle (Accessed: January 2022). Why Aren’t There Giant Insects? (2012) SciShow. Available at: https://www.youtube.com/watch?v=179FuGuk1qE&list=PLB3FCEEAC84884760&index=50 (Accessed: January 2022).