Whether associated with the deadly reputation of the Black Widow or the fictional bite that transformed Spider-Man, fangs have become one of the most recognizable features of spiders. Their evolutionary story, however, began long before modern spiders appeared.

A new study published in Nature traces the origins of this powerful hunting tool to Urokodia, a small marine creature that lived during the early Cambrian Period.

The Ancient Origins of Spider Fangs

Spiders belong to a large group of invertebrates called chelicerates, which also includes scorpions and ticks. More than 100,000 chelicerate species have been described.

These animals have jointed limbs and hard external skeletons. Their defining feature is a pair of specialized appendages called chelicerae, located near the front of the body. Depending on the species, chelicerae can function as pincers or fangs that grip, pierce, or stab prey.

Urokodia fossils were discovered at the renowned Chengjiang fossil site in Yunnan Province in southern China. The study was published on the 42nd anniversary of the site’s discovery.

The creature measured only around 2-3 cm in length. It had large eyes extending from stalks at the front of its body, along with a segmented skeleton and jointed limbs attached beneath its narrow frame. Its appearance bears little obvious resemblance to the spiders and scorpions that descended from its broader evolutionary lineage.

X-Rays Reveal Preserved Soft Anatomy

Researchers from Yunnan University, China, and the University of Leicester used X-ray technology to examine the rock surrounding the fossil. The scans revealed that much of the animal’s soft anatomy had remained preserved in a mummified state for hundreds of millions of years.

Most importantly, the researchers identified two pincer-like appendages positioned just behind the creature’s eyes. These structures represent an early form of chelicerae and provide evidence of the evolutionary beginnings of the pincers and fangs seen in chelicerates today.

The fossil also preserves features on Urokodia‘s legs that may have served as book gills, allowing the animal to breathe underwater. Similar respiratory structures are still found in aquatic chelicerates such as horseshoe crabs.

A Successful Lineage of Hunters

Chelicerates have become one of the most successful animal groups in both marine and terrestrial environments. Those that moved onto land developed into highly effective predators, and fossils show that their ancestors had already been hunting for hundreds of millions of years.

Despite the frightening image of spiders presented in movies such as Arachnophobia, most species pose no danger to people. Their venom and bites evolved to subdue prey that is far smaller than a human.

The research was led by Professor Yu Liu of Yunnan University, who is also a Visiting Professor at the University of Leicester.

Professor Liu said: “We were using X-ray tomography analysis of these fossils to reveal their soft anatomy buried in the rocks for hundreds of millions of years, when suddenly we noticed the pincer-like limbs at the front of the animal. We knew immediately that this was a very exciting fossil and indeed a distant ancestor of living chelicerates like scorpions and spiders.”

A Window Into the Dawn of Animal Life

Urokodia lived within a rich marine ecosystem during a crucial period in the history of animal evolution. The Chengjiang fossils preserve evidence of more than 200 types of animals that inhabited the oceans over 500 million years ago.

Co-author Professor Mark Williams from the University of Leicester School of Geography, Geology and the Environment said: “Urokodia was part of an ancient ecosystem of over 200 different types of animals living in the seas over 500 million years ago. These spectacularly preserved fossils provide real insights into how life was evolving on our planet at the very dawn of animals.”

This study was supported by a grant from the Department of Science and Technology of Yunnan Province (202401BC070012) to Professor Yu Liu, who is further funded by the Yunnan Revitalization Talent Support Program.

The result also marks progress toward using hydrogen for cleaner energy production. Unlike natural gas, hydrogen can be produced using renewable energy sources. Earlier this year, the KIT team also became the first to generate electricity with a hydrogen gas turbine that does not rely on a mechanical compressor.

Hydrogen Turbine Runs for More Than Five Minutes

Earlier experiments could continue for only fractions of a second because longer operation would cause the combustion chambers to melt. The new test extended the operating time to more than five minutes.

“This is an important step toward highly efficient and flexible hydrogen energy for a fossil-free energy system,” explains Professor Daniel Banuti, Director of the Institute of Thermal Energy Technology and Safety (ITES).

A key benefit of the design is that it does not require energy to compress air before combustion begins.

“A conventional gas turbine, such as those used in power plants or under aircraft wings, consumes about 50 percent of its power to compress air to the high pressure needed for efficient combustion — power that is then unavailable for electricity generation,” Banuti explains.

Detonation Waves Replace the Compressor

The new turbine is built around pressure-gain combustion. Conventional gas turbines use a mechanical compressor to raise air pressure, a process that can consume roughly half of the turbine’s power output.

The KIT system creates the required pressure inside the combustion chamber instead. Detonation waves form through a fluid mechanical instability involving wave and vortex patterns in the flowing gases. This allows the turbine to operate without a mechanical compressor.

Removing the compressor could reduce energy losses, lower the number of moving components, and improve overall efficiency.

Why Hydrogen Works So Well

The technology can operate with fuels other than hydrogen, but hydrogen is especially suitable because it reacts very quickly and can produce stable increases in pressure.

Researchers say the approach could eventually support turbines that are lighter, less expensive, and highly efficient. Potential applications include electricity generation and, over the longer term, aviation.

Generating Electricity Without Mechanical Compression

Connecting the combustion chamber to a turbine and converting its intense combustion into electricity created an additional engineering challenge. The rapid and powerful reactions inside the chamber make it difficult to transfer energy to the turbine in a stable way.

“This is extremely difficult because the very fast and intense combustion processes in the chamber make stable energy transfer to the turbine challenging. We are the first to successfully operate such a turbine and generate electricity in the process,” says Banuti.

Until now, scientists have had limited information about how much of this carbon returns to the atmosphere and how much remains trapped in the ocean. Researchers from the Alfred Wegener Institute and MARUM – Centre for Marine Environmental Sciences at the University of Bremen have now examined this process along the permafrost coast of Qikiqtaruk (Herschel Island) in Canada.

By studying sediment cores, the team found that large amounts of carbon from land are preserved in the seafloor. They also discovered that marine microorganisms behave like selective eaters, favoring fresh carbon from the ocean over older carbon released from permafrost. The findings were published in Nature Geoscience.

Vast Carbon Stores Are Beginning to Thaw

Permafrost ecosystems on Arctic land contain about 1,300 gigatonnes of organic carbon, much of it from plant remains. Another 400 gigatonnes are stored in ocean sediments and river deltas.

As the planet warms, the Arctic is heating faster than any other region. This rapid temperature rise is causing frozen ground to thaw and coastlines to break apart. Carbon that was previously locked in the soil can then reach the Arctic Ocean through rivers and coastal erosion.

“Consequently, up to 0.02 gigatonnes are entering the sea each year, and according to forecasts, this outflow could rise by 70 to 150 percent by the year 2100,” says Dr. Manuel Ruben, lead author of the study from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). “However, how much of this is released back into the atmosphere as a greenhouse gas and how much is stored in the seabed has, until now, been largely unknown.”

Resolving that uncertainty is important because scientists need to know where the carbon ultimately ends up to estimate how thawing permafrost could affect the climate.

Sediment Cores Reveal Where the Carbon Goes

To investigate, the researchers collected sediment cores from several locations off the coast of Herschel Island. These cores contain layers of material deposited over roughly 50 years.

The results showed that only a relatively small share of the carbon swept into the ocean becomes part of the active carbon cycle.

“Although the sea here carries away huge quantities of organic carbon from the coast, surprisingly little of it ends up in the ocean’s active carbon cycle,” says Manuel Ruben. “Microorganisms convert around ten percent of the organic carbon from the sediments into gases, which rise into the water and can then enter our atmosphere.”

Most of the remaining carbon stays buried in the seabed.

Chemical Clues Track Microbial Activity

The scientists analyzed the composition of the sediment cores and measured how quickly material from the permafrost accumulated on the ocean floor.

They also studied dissolved inorganic carbon found in tiny spaces between sediment particles, known as pore water. These measurements reveal how much CO2 microorganisms have released after consuming organic material.

The isotopic makeup of the pore water helped the team determine where that material came from.

“Carbon isotopes represent our atomic indicators that can identify the food source of the microorganisms,” says Prof. Gesine Mollenhauer, a geochemist at the AWI and co-spokesperson for the ‘The Ocean Floor – Earth’s Unexplored Interface’ cluster of Excellence. “The ¹³C isotope, for example, tells us whether they have consumed carbon from land or from the sea. By way of the ¹⁴C isotope, we were able to determine whether the single-celled organisms preferred old organic carbon from permafrost or fresh organic carbon from algae remains.”

“Gourmet” Bacteria Prefer Fresh Carbon

The results suggest that the organisms living in the sediment are not equally interested in every type of carbon.

“The sediment is home to ‘gourmet’ bacteria that apparently prefer fresh carbon stemming from, for example, more recent algal remains over the ‘old’ carbon from permafrost deposits,” explains Gesine Mollenhauer.

Because the microbes favor fresh marine material, older carbon from thawing permafrost may contribute less to atmospheric greenhouse gas levels than scientists once feared.

However, the researchers caution that the full picture is not yet clear.

“However, we do need further research here. This is because some of the organic carbon from the permafrost may already have been broken down before it reaches the seabed.”

Coastal Carbon Could Reshape Arctic Ecosystems

The movement of carbon from land into the ocean may affect more than greenhouse gas emissions. It can also change the chemistry and biology of coastal waters that support food resources for local communities.

Sediment released by coastal erosion can reduce the amount of sunlight entering the water. Freshly eroded fragments make the coastal ocean cloudy, while dissolved organic carbon can darken the water.

That loss of light can affect single-celled organisms such as algae, which need sunlight to produce biomass and oxygen. This primary production supports a wider food web that includes fish, crustaceans and seals.

The researchers plan to explore these connections further during the international ‘Arctic Pulse’ campaign scheduled for 2027. Scientists will carry out coordinated observations from the Polarstern research icebreaker, aboard AWI research aircraft and at sites on land. Their goal is to understand how rapid environmental change is transforming Arctic ecosystems.

Improving Arctic Climate Models

“Our study shows, more precisely than ever before, how much carbon is safely stored in the seabed – and just how much of the decomposed material actually originates from the old permafrost,” says Manuel Ruben. “This provides an important foundation for climate models that can predict the consequences of permafrost thawing for the global climate.”