What it is
A myriapod, related to today's millipedes. It crossed the forest floor, and it ate dead plants, as far as anyone can tell.
Why it matters
The largest piece anyone has ever found is a 76 centimeter shell it molted and walked away from, found on a beach in Northumberland, in England. Scale the rest to that shell and you get two meters, maybe two and a half, and about fifty kilograms of it. Longer than a person is tall. Every length past the shell is an estimate.
A head at last
For more than a century, nobody had seen its head. In 2024, scientists scanned fossils of young Arthropleura from coal mines in France and found antennae, eyes and jaws. The head had features of a centipede, while the body was built like a millipede's. The team still places it with the millipedes.
Read the sources
- The largest arthropod in Earth history: new Arthropleura remains from Northumberland · Journal of the Geological Society (2021)
- Head anatomy of the Carboniferous giant Arthropleura · Science Advances (2024)
- Scientists unveil the head of a prehistoric giant arthropod · European Synchrotron Radiation Facility (2024)