Quote:Millipedes 'as big as cars' once roamed Northern England, fossil find reveals
by University of Cambridge

Reconstruction of the giant millipede Arthropleura, which lived in the Carboniferous period, 326 million years ago. Credit: Neil Davies
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."

Fossilised section of the giant millipede Arthropleura, found in a sandstone boulder in the north of England. Credit: Neil Daves
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.
The fossil was brought back to Cambridge so that it could be examined in detail. It was compared with all previous records and revealed new information about the animal's habitat and evolution. The animal can be seen to have only existed in places that were once located at the Equator, such as Great Britain during the Carboniferous. Previous reconstructions have suggested that the animal lived in coal swamps, but this specimen showed Arthropleura preferred open woodland habitats near the coast.

Scientists remove a fossil of the giant millipede Arthropleura from a northern England beach. Credit: Neil Davies
There are only two other known Arthropleura fossils, both from Germany, and both much smaller than the new specimen. Although this is the largest Arthropleura fossil skeleton ever found, there is still much to learn about these creatures. "Finding these giant millipede fossils is rare, because once they died, 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 fossilized head, so it's difficult to know everything about them."

The great size of Arthropleura has previously been attributed to a peak in atmospheric oxygen during the late Carboniferous and Permian periods, but because the new fossil comes from rocks deposited before this peak, it shows that oxygen cannot be the only explanation.
The researchers believe that to get to such a large size, Arthropleura must have had a high-nutrient 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 fed off other invertebrates and even small vertebrates such as amphibians," said Davies.
Arthropleura animals crawled around Earth's equatorial region for around 45 million years, before going extinct during the Permian period. 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.
The fossil will go on public display at Cambridge's Sedgwick Museum in the New Year.
Neil Davies is a Fellow of Churchill College, Cambridge.

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Would have been something to see the world the way it was way back when...and survive !! https://phys.org/news/2021-12-millipedes...thern.html

Arthropleura also lived here back then. Trackways from Arthropleura are often found in the slate stone layers between layers of coal in the mines here. Most of them are about a foot wide, two parallel lines of tiny feet on a big body.

I find some curiosities in the article, For example, two specimens from coal mines and one from a sandstone beach are not a huge sample to draw conclusions from, so I question whether Arthropleura "preferred" sandy beaches as the article states. I think it may have been more cosmopolitan than that, and lived in a variety of environments. When 2/3 of known samples come from former coal swamps, it's hard to draw the conclusion that they preferred to live somewhere else.

I also have to wonder how and why they worked "global warming" in there as the reason for Arthropleura's extinction. This area sat around the equator at that time due to continental drift, as did that area of England. The AVERAGE daily temperature here was 111 degrees Fahrenheit, and warming beyond that would have been a sight to behold, not to mention not attested to in the geological record... yet Arthropleura thrived under such conditions. Furthermore, COOLING leads to dryer conditions, not warming. Warming leads to moister, wetter conditions because the warm air holds more humidity than cold air does, Cooling, for example, is what led to the drier conditions and desertification of the Permian period.

It has been claimed that Arthropoleura was a vegetarian, living off detrius from the forest floor, rather than a carnivore as centipedes are today. That conclusion was drawn apparently from the pollen grains found in fossilized Arthropleura gut tracts. But again one, or even 6, specimens are not a huge sample to draw sweeping conclusions from. It may be that they were omnivorous, or that the pollen came from the gut of one of their victims instead.

A few years ago there was a British TV show called "Primeval", and Arthropleura was featured in one of the episodes of that series, battling to the death with Our Heros of the series after coming through one of the ubiquitous "time portals" that the show was based upon. That Arthropluera was a bit larger than the real thing, for dramatic effect I suppose, but was otherwise pretty accurate, as far as current science knows.

The ones here were estimated to be about 8 feet long, that one clocks in at about a foot longer than that.

The article mentions an overabundance of oxygen as the reason for insect gigantism in those days, then goes on to discount that theory saying this specimen lived before the oxygen peak -but that does not necessarily rule out overabundant oxygen as a contributing factor. Oxygen levels peaked at 32% in the late Carboniferous, but there had to be a lead-up to that level. I'm not sure what the levels were 326 million years ago, but I'm willing to bet they were still well above the current oxygen poverty levels of 21%.

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Something that big would weigh...Allot ! They say there is around 4 billion tons of space dust that falls to earth every year. Back then the solar system was probably more dusty than it is today. Maybe the earth rotational speed was faster than today but whatever that was one heavy bug and I doubt it could be frisky (regardless of atmosphere) in today's world due to gravity alone..

(12-27-2021, 09:08 AM)727Sky Wrote: Something that big would weigh...Allot ! They say there is around 4 billion tons of space dust that falls to earth every year. Back then the solar system was probably more dusty than it is today. Maybe the earth rotational speed was faster than today but whatever that was one heavy bug and I doubt it could be frisky (regardless of atmosphere) in today's world due to gravity alone..

I figured it out given the average rate of yearly rotational decline of the Earth, and days back then averaged 18 hours, 21 minutes long.

The moon was also closer, and looked a little bigger. It moves away from the Earth at about an inch a year, so it was, at the time, about 326 million inches closer, 27 million feet, 5145 miles).

When the oxygen peaked at 32%, forest fires were all over the place (sparked by lightning and such) because of the increased oxygen to fuel ratio. They still find ash layers from it in coal mines.

The article estimate that Arthopleura weighed 50 kg/ 110 lbs. Now that's a big damned bug! The last centipede I caught fit into a wine bottle. No such luck with that bugger!

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(12-27-2021, 03:59 PM)Ninurta Wrote:

(12-27-2021, 09:08 AM)727Sky Wrote: Something that big would weigh...Allot ! They say there is around 4 billion tons of space dust that falls to earth every year. Back then the solar system was probably more dusty than it is today. Maybe the earth rotational speed was faster than today but whatever that was one heavy bug and I doubt it could be frisky (regardless of atmosphere) in today's world due to gravity alone..

I figured it out given the average rate of yearly rotational decline of the Earth, and days back then averaged 18 hours, 21 minutes long.

The moon was also closer, and looked a little bigger. It moves away from the Earth at about an inch a year, so it was, at the time, about 326 million inches closer, 27 million feet, 5145 miles).

When the oxygen peaked at 32%, forest fires were all over the place (sparked by lightning and such) because of the increased oxygen to fuel ratio. They still find ash layers from it in coal mines.

The article estimate that Arthopleura weighed 50 kg/ 110 lbs. Now that's a big damned bug! The last centipede I caught fit into a wine bottle. No such luck with that bugger!

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Good figuring IMO !

I'm glad they were millipedes and not centipedes, a car-sized centipede would be terrifying. 



Just look at those fangs, which are actually modified limbs.  I'd shoot that thing.