A massive centipede, believed to be the world’s largest arthropod, was recently discovered in the United Kingdom. Researchers found the fossilized exoskeleton of the ancient millipede-like creature, which would have measured as long as a vehicle, and probably lived between 359 and 299 million years ago, during the Carboniferous Period.
The species, known as Arthropleura, was already known to researchers, but the newly discovered exoskeleton reveals that these ancient creatures could grow much larger than previously thought. The fossil, found in 2018, is a piece of a 326 million-year-old Arthropleura fossil discovered on a beach in Northumberland, northeast England, inside a broken block of sandstone.
According to the researchers, the molted exoskeleton they found would have belonged to an Arthropleura around 8.5 feet long and weighing about 110 pounds. The discovery is significant as these creatures would have been the largest animals on land during the Carboniferous period.
It was fortunate that the fossil was visible since molted exoskeletons do not typically fossilize effectively due to fast degradation. The Arthropleura fossil appears to have filled with sand shortly after molting and ended up in a fossilized river channel, where it was swiftly embedded in other silt.
The researchers estimate that the Arthropleura was widespread near the equator and probably ate trees, plants, and nuts, although the number of legs it possessed is uncertain. This particular individual’s trackways indicate that it had at least 20 legs. While the reason for their extinction is not clear, competition with other species and reduced resources likely contributed to their downfall.
During the Carboniferous period, the tropical environment and lack of predators and large creatures enabled Arthropleura to develop to such amazing sizes. A move in the equator to its current location during the early Permian Period, 299 million to 252 million years ago, is believed to have modified the environment and allowed the earliest reptiles to survive on land. Eventually, increased competition and reduced resources led to their extinction.