In January 2018, researchers from the University of Cambridge stumbled upon a fossil in a block of sandstone that had fallen from a cliff in Northumberland. “It was a complete fluke of a discovery,” said Dr Neil Davies from Cambridge’s Department of Earth Sciences in a release. “The way the boulder had fallen, it had cracked open and perfectly exposed the fossil, which one of our former PhD students happened to spot when walking by.”
The team says that this is the largest-ever fossil of a millipede and the creature – estimated to have been around 2.7 metres long and 50 kgs in weight – lived about 326 million years ago. It belongs to the Arthropleura genus. The results were published in the Journal of the Geological Society.
“Finding these giant millipede fossils is rare, because once they die their bodies tend to disarticulate, so it’s likely that the fossil is a molted carapace that the animal shed as it grew,” said Davies. “We have not yet found a fossilised head, so it’s difficult to know everything about them.”
The researchers believe that the millipede had a highly-nutritious diet. “While we can’t know for sure what they ate, there were plenty of nutritious nuts and seeds available in the leaf litter at the time, and they may even have been predators that feed off other invertebrates and even small vertebrates such as amphibians,” said Davies.
Members of the Arthropleura genus are known to have gone extinct during the Permian period about 250 million years ago. “The cause of their extinction is uncertain, but could be due to global warming that made the climate too dry for them to survive, or to the rise of reptiles, who out-competed them for food and soon dominated the same habitats,” adds the release.
The fossil will go on public display at Cambridge’s Sedgwick Museum from January 1, 2022.