The fossil remains of living things are called carboniferous arthropods, about 326 million years ago, more than 654.38 million +0 million years ago in the dinosaur era. Fossils show that arthropods are the largest invertebrates known so far, which are larger than the ancient sea scorpions whose owners were previously recorded.

This specimen was found on the beach in Northumberland about 40 miles north of Newcastle. It is composed of several articulated exoskeleton parts, similar in form to modern millipedes. This is only the third such fossil discovered so far. It is also the oldest and largest: this part is about 75 centimeters long, while primitive creatures are estimated to be about 2.7 meters long and weigh about 50 kilograms. The research results were published in the Journal of Geological Society.

The fossil was discovered in June 20 18 in a large sandstone that fell from a cliff in Howick Bay, Northumberland to the beach. The first author of the paper, Dr. Neil Davis of the Department of Earth Sciences at Cambridge University, said: "This is a complete accidental discovery." "The way the boulder fell, it cracked and exposed the fossils perfectly, which was discovered by accident when a former doctoral student passed by."

Unlike the cool and humid weather in this area today, northumberland was more tropical during the Carboniferous period, when Britain was close to the equator. Invertebrates and early amphibians feed on vegetation scattered around a series of streams and rivers. The researchers identified the specimens in the fossil river and found that it was possible that the exoskeleton of the molting segment of arthropod was filled with sand and remained for hundreds of millions of years.

The fossil was extracted in May, 20 18 with the permission of natural England and the landlord Howick Manor. "This is an incredibly exciting discovery, but the fossil is so big that we need four people to lift it up the cliff," Davis said.

Fossils were taken back to Cambridge for detailed examination. Compared with all previous records, it reveals new information about animal habitat and evolution. It can be seen that this animal only existed in places that used to be at the equator, such as Carboniferous England. Previous reconstruction shows that this animal lives in coal swamps, but this specimen shows that arthropods prefer open woodland habitats near the coast.

Scientists took out fossils of giant millipede arthropods from beaches in northern England. Acknowledgement: Neil Davis has only two other known arthropod fossils, both from Germany, and both are much smaller than the new specimens. Although this is the largest fossil skeleton of arthropods found so far, there is still a lot to know about these creatures. "It is rare to find these giant millipede fossils, because once they die, their bodies often lose contact, so these fossils are probably the molting of animals during their growth," Davis said. "We haven't found head fossils yet, so it's hard to know everything about them."

The huge size of arthropods was previously attributed to the peak of oxygen in the atmosphere in the late Carboniferous and Permian, but since the new fossils came from rocks deposited before the peak, it shows that oxygen cannot be the only explanation.

Researchers believe that to grow to this size, arthropods must adopt a highly nutritious diet. "Although we are not sure what they ate, the fallen leaves contain a lot of nutritious nuts and seeds, and they may even be predators, feeding on other invertebrates and even small vertebrates such as amphibians," Davis said.

Arthropods crawled in the equatorial region of the earth for about 45 million years, and then died out in Permian. The reason for their extinction is uncertain, but it may be that the climate is too dry to survive due to global warming, or the rise of reptiles, which overtook them in food and quickly ruled the same habitat.

The fossil will be exhibited at the sedgwick Museum in Cambridge in the New Year.