Scientists say they have discovered the largest-ever fossil of a giant millipede on a Northumberland beach, which was found by chance after a section of cliff fell onto the shore.

The fossil segment was first spotted in 2018 when a large block of sandstone fell on to a beach at Howick Bay.

This millipede, known as Arthropleura, would have approximately weighed 50kg and have measured around 2.7m long.

Remains of the creature date from the Carboniferous Period, more than 100 million years before the Age of Dinosaurs.

Only a 75cm long segment was found, and scientists believe it represents just a section of the creature’s exoskeleton that it shed near a river bed.

It is just the third such fossil ever found and is also the oldest and largest.

Your Local Guardian: Illustration of the Arthropleura millipede (J.W. Schneider/TU Bergakademie Freiberg/PA)Illustration of the Arthropleura millipede (J.W. Schneider/TU Bergakademie Freiberg/PA)

How was the giant millipede fossil found?

A former PhD student who was walking along the coast in January 2018 spotted it in a large block of sandstone that had fallen from the cliff.

Dr Neil Davies, from Cambridge University’s Department of Earth Sciences and lead author of a paper on the fossil, told the PA News Agency: “It was a complete fluke of a discovery.

“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.

“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 fed off other invertebrates and even small vertebrates such as amphibians.”

The creatures crawled around the equatorial region for around 45 million years, before going extinct, possibly due to global warming that made the climate too dry for them, or due to the rise of reptiles, who out-competed them for food.

The fossil will go on public display at Cambridge’s Sedgwick Museum in the New Year.