The largest-ever fossil of a giant millipede, as big as a car, was found on a beach in the north of England.
The remains of a creature called Arthropleura were found over 100 million years before the Age of Dinosaurs. The ancient sea scorpions were the previous record holders, but the fossil shows that the arthropod was larger.
The specimen was found on a beach in the north of England and is made up of multiple articulated segments. It's the third fossil ever found. The segment is about 75 centimetres long and the original creature is thought to have weighed 50 kilograms. The results are reported in a journal.
The fossil was found in a large block of sandstone that had fallen from a cliff at Howick Bay. The paper's lead author, Dr Neil Davies from Cambridge's Department of Earth Sciences, said it was a complete fluke. One of our former PhD students spotted the fossil when he was walking by, because the boulder cracked open and exposed it.
In the Carboniferous Period, when Great Britain was located near the Equator, the weather in the region was more tropical. The vegetation around the creek and rivers was home to invertebrates and early amphibians. The specimen was found in a fossilised river channel, and it was likely a moulted segment of the Arthropleura's exoskeleton that filled with sand for hundreds of millions of years.
Natural England gave permission for the fossil to be taken from the Howick Estate. It took four of us to carry the fossil up the cliff face, but it was an exciting find.
The fossil was brought back to Cambridge so that it could be studied in detail. New information about the animal's habitat and evolution was revealed when it was compared with previous records. The animal can be seen only in places that were once located at the equator, such as Great Britain during the Carboniferous. The specimen showed that the animal preferred open woodland over coal swamps.
The new specimen is the only one of its kind, and it is the only one that is smaller than the other two. There is still much to learn about the creatures that were found in this skeleton. The fossils of giant millipede are rare because their bodies tend to disarticulate, so it's likely that the fossil is a moulted carapace that the animal shed as it grew. It's difficult to know everything about them because they haven't found a fossilised head.
The new fossil shows that oxygen cannot be the only explanation for the large size of Arthropleura, because it comes from rocks deposited before the peak of atmospheric oxygen.
The researchers think that the large size of the arthropod must have been due to a high-nutrient diet. There were plenty of nuts and seeds available in the leaf litter at the time, and they may have been a source of food for other animals.
During the 45 million years that the arthropods crawled around the Earth's equator, they went extinct. Global warming could be the cause of their extinction, as it could have made the climate too dry for them to survive.
The fossil will be on display in Cambridge in the new year.
Neil Davies is a fellow of the college. The Natural Environment Research Council supported the research.
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The University of Cambridge provided the materials. Sarah Collins wrote the original. The original text of the story is free to use. Content can be edited for style and length.
