The internal anatomy of a prehistoric creature the size of a poppy seed has been revealed in “astonishing detail”.

Researchers used powerful X-rays to scan the 520-million-year-old fossil.

The results, published in the journal Nature, reveal its microscopic blood vessels and nervous system.

It is a peek inside the body of one of the earliest ancestors of modern insects, spiders and crabs.

Lead researcher Dr Martin Smith said this was a dream fossil, in part because it was preserved in its larval, or immature, stage – when its body was still developing.

“Looking at these early stages really is the key to understanding how those adult [body shapes] are formed – not just through evolution but through development.

“But larvae are so tiny and fragile, the chances of finding one fossilised are practically zero – or so I thought.”

Dr Smith’s colleagues found the fossil in a pile of “prehistoric grit” during a study of half-billion-year-old rock deposits in the north of China known to contain microscopic fossils.

“Our collaborators in China have large amounts of this stuff, which they dissolve it in acid and these little bits fall out,” Dr Smith said.

A team of technicians at Yunnan University spent years sifting through the material and picking fossils out of the dust.

After examining this particular specimen under the microscope during a trip to China, Dr Smith said, he had realised it was “something very special” and asked if he could bring it back to the UK to have a closer look.

The team mounted the fossil on the head of a pin in order to scan it with intense X-rays at Oxford’s Diamond Light Source facility. That is where its internal secrets were revealed.

“When I saw the amazing structures preserved under its skin, my jaw just dropped,” Dr Smith said.

Researchers generated three-dimensional images of miniature brain regions, digestive glands, a primitive circulatory system and even traces of the nerves supplying the larva’s simple legs and eyes.

Its brain cavity, which is divided into segments, has revealed the ancestral “nub” of the specialist, segmented heads of modern insects, spiders and crabs that later evolved their various appendages, such as antennae, mouthparts and eyes.

Study co-author, Dr Katherine Dobson, of the University of Strathclyde, said the natural fossilisation had “achieved almost perfect preservation”.

Dr Smith said this might have been caused by high concentrations of phosphorus in the ocean where this larva briefly lived and died.

“It’s washed into the oceans when rocks erode on land,” he said.

“And that phosphorus seems to have flooded the tissues of our fossil,” essentially crystallising its tiny body.

The Prince of Wales has issued an urgent call to end environmental destruction and to “make peace with nature”.

“We are living at odds with the natural world – and it is buckling under the pressure of our actions,” he said, in a video message played at a Campaign for Nature event at the General Assembly of the United Nations, in New York.

Prince William said climate change and the prospect of a million species facing extinction represented the most pressing “existential threat”.

His speech followed the announcement of the finalists for the fourth year of the prince’s Earthshot awards for international ideas to improve sustainability.

“If we are to keep this planet liveable for our children and grandchildren, we must act urgently,” the prince said, in a speech that had echoes of the eco-campaigning of his father, King Charles III.

“We can and must change our relationship with the natural world.”

Such a reset in the relationship would mean economic changes, “realigning financial flows from destruction to regeneration”.

“It means change,” the prince said, calling on international leaders “to halt the unsustainable production and consumption of natural resources”.

“We must act to save our rivers, oceans, savannas, mangroves and forests, as well as the communities that protect and live alongside them,” he said.

The 15 finalists for this year’s Earthshot awards were also announced in New York, recognising innovative ways of protecting the environment, drawn from 2,500 nominations, including:

• a project to reduce waste and cut air pollution in Ghana
• building a social enterprise around farming seaweed in the Philippines
• solar-powered refrigeration in Kenya
• earthquake-resilient bricks in Nepal
• a scheme in Kazakhstan to protect a type of antelope on the brink of extinction
• a project in Scotlant to feed fish using a by-product from distilling whisky

The five winners, to be revealed at an event in Cape Town, South Africa, in November, will receive £1m each.

Meanwhile, the Princess of Wales is continuing her return to work, after the end of her chemotherapy.

On Tuesday, she held a meeting in Windsor Castle, to plan her annual Christmas carol concert in Westminster Abbey.

Central Europe’s devastating floods were made much worse by climate change and offer a stark glimpse of the future for the world’s fastest-warming continent, scientists say.

Storm Boris has ravaged countries including Poland, the Czech Republic, Romania, Austria and Italy, leading to at least 24 deaths and billions of pounds of damage.

The World Weather Attribution (WWA) group said one recent four-day period was the rainiest ever recorded in central Europe – an intensity made twice as likely by climate change.

On a positive note, the storm was well forecast, meaning some regions were better prepared for it, likely avoiding more deaths.

Scientists at WWA work out how much of a role climate change played in an extreme weather event by comparing it with a model of how bad that storm, drought or heatwave might have been in a world where humans hadn’t been burning fossil fuels for nearly 200 years.

The kind of rainfall unleashed by Boris is thankfully still rare – expected to occur about once every 100-300 years in today’s climate, which has warmed by about 1.3C due to greenhouse gas emissions.

But if warming reaches 2C, similar episodes will become an extra 5% more intense and 50% more frequent, the WWA warned.

Without more ambitious climate action, global warming is expected to reach around 3C by the end of the century.

“This is definitely what we will see much more of in the future,” said Friederike Otto, senior lecturer in climate science at Imperial College London and co-author of the WWA study.

“[It] is the absolute fingerprint signature of climate change […] that records are broken by such a large margin.”

The record rains fit into the broader pattern of how Europe’s climate is changing in a warming world.

Europe is the fastest-warming continent. The last five years were on average around 2.3C warmer than the second half of the 19th Century, according to the Copernicus climate service.

This not only brings much more frequent and intense heatwaves, but also more extreme rainfall, particularly over north and central Europe. The picture is more complicated in southern Europe, due to shifts in large-scale weather patterns.

The simplest reason for more intense rainfall in a hotter world is that a warmer atmosphere can hold more moisture – about 7% for every 1C. This extra moisture can lead to heavier rainfall.

One reason Boris has produced so much rain is that the weather system got ‘stuck’, dumping huge amounts of water over the same areas for days.

There is some evidence that the effects of climate change on the jet stream – a band of fast-flowing winds high up in the atmosphere – may make this ‘stalling’ phenomenon more common. But this is still up for debate.

Even if we don’t get more ‘stalled’ weather systems in the future, climate change means that any that do get stuck can carry more moisture and therefore be potentially disastrous.

“These weather patterns occurred in a warmer climate because of our greenhouse gas emissions, [so] the intensity and volume of rainfall was larger than it would have otherwise been,” explains Richard Allan, professor in climate science at the University of Reading.

Weather forecasts are continually improving, and in this case the huge levels of rainfall that triggered the floods were forecast several days in advance.

That meant flood preparations could be put in place.

That’s partly why the death toll was not as bad as previous major flooding in 1997 and 2002, even though the recent rain was heavier in many places and the floods covered a larger area.

“There has been a lot of money spent after the previous two floods to [install and update] the flood defences,” explains Mirek Trnka of the Global Change Research Institute in the Czech Republic, one of the countries most affected by the flooding.

In the city of Brno, for example, where Prof Trnka is based, not all of the flood defences had been completed, but the advanced warning allowed authorities to strengthen areas where there was still work to be done.

Not everywhere in Europe has been as fortunate. The EU has pledged €10bn (£8.3bn) in emergency repairs to help affected areas.

“It shows just how expensive climate change is,” says Dr Otto.

Over recent decades, improved flood protection has largely shielded communities from increased impacts.

But there are concerns that rising temperatures – and so ever increasing extreme rainfall – could make them ineffective.

“The [severity of the] flood events is going to increase considerably in the future, so if you keep the flood protections at the same level as they are today, the impacts may become unbearable for societies in Europe,” explains Francesco Dottori of IUSS in Pavia, Italy.

There is of course a clear way to stop these rainfall events from getting ever worse – cutting emissions of planet-warming gases such as carbon dioxide.

“Our simulations show that if you are able to keep future global warming below 1.5C, which is one of the targets of the Paris agreement, then future flood damage will be cut by half compared to the [business as usual] scenario,” Dr Dottori adds.

Otherwise, we know what will happen to these events in the future, Prof Allan says.

“The intensity of rainfall and these weather events will only get worse.”

Map by Muskeen Liddar.