Millipedes 'as big as cars' once roamed Northern England, fossil find reveals:
The largest-ever fossil of a giant millipede—as big as a car—has been found on a beach in the north of England.
The fossil—the remains of a creature called Arthropleura—dates from the Carboniferous Period, about 326 million years ago, over 100 million years before the Age of Dinosaurs. The fossil reveals that Arthropleura was the largest-known invertebrate animal of all time, larger than the ancient sea scorpions that were the previous record holders.
The specimen, found on a Northumberland beach about 40 miles north of Newcastle, is made up of multiple articulated exoskeleton segments, broadly similar in form to modern millipedes. It is just the third such fossil ever found. It is also the oldest and largest: the segment is about 75 centimeters long, while the original creature is estimated to have measured around 2.7 meters long and weighed around 50 kilograms. The results are reported in the Journal of the Geological Society.
The fossil was discovered in January 2018 in a large block of sandstone that had fallen from a cliff to the beach at Howick Bay in Northumberland. "It was a complete fluke of a discovery," said Dr. Neil Davies from Cambridge's Department of Earth Sciences, the paper's lead author. "The way the boulder had fallen, it had cracked open and perfectly exposed the fossil, which one of our former Ph.D. students happened to spot when walking by."
Unlike the cool and wet weather associated with the region today, Northumberland had a more tropical climate in the Carboniferous Period, when Great Britain lay near the Equator. Invertebrates and early amphibians lived off the scattered vegetation around a series of creeks and rivers. The specimen identified by the researchers was found in a fossilized river channel: it was likely a molted segment of the Arthropleura's exoskeleton that filled with sand, preserving it for hundreds of millions of years.
The fossil was extracted in May 2018 with permission from Natural England and the landowners, the Howick Estate. "It was an incredibly exciting find, but the fossil is so large it took four of us to carry it up the cliff face," said Davies.
More information: The largest arthropod in Earth history: insights from newly discovered Arthropleura remains (Serpukhovian Stainmore Formation, Northumberland, England), Journal of the Geological Society (2021). DOI: 10.1144/jgs2021-115J
(Score: 1) by Michael on Tuesday December 21 2021, @07:43PM (1 child)
I'd hazard a guess that a moderately sized individual could be comfortable today if nothing too strenuous was required of it. 326 million years ago the o2 level was low to mid twenties. Even at its peak 250ish mya, o2 didn't top thirty. If oxygen was the limiting factor for their maximum size (may not be), they probably would have stunted growth and be generally more lethargic and fragile than usual in our atmo, but unlikely to outright die.
If these sorts of things were around 350mya, those ones would have had a couple percent less oxygen then we have today, so it's even possible they wouldn't even notice.
(Score: 0) by Anonymous Coward on Wednesday December 22 2021, @02:14AM
Today's insects are limited in size mostly by oxygen, but that doesn't mean these were. They probably just didn't move very fast. Their evolution and extinction just doesn't line up with the changing oxygen levels.
In the time when these were alive, the only land animals were arthropods, like them. There were a few primitive amphibians, that could barely come out of the water. Those early amphibians were big and fierce, but limited. More like crocodiles than wolves or tigers.
Once reptiles turned up, and land animals could go wherever they wanted, these giant millipedes became food.