Latest news with #Keurbos
Yahoo
07-05-2025
- Science
- Yahoo
Marine fossil found in South Africa is one of a kind, thanks to unusual preservation
A fossilised creature found in a South African roadside quarry 25 years ago has finally got an official name. The small, segmented, crustacean-like creature, dated to 444 million years ago, can now be introduced as Keurbos susanae. It belongs to the arthropod group of animals, which accounts for about 84% of all known species that exist today, including insects, spiders and crabs. Palaeontologist Sarah Gabbott explains what's so unusual about her discovery, which she named as part of the process of describing it scientifically. What can you tell us about this creature and the environment it lived in? The fossil is about 50cm long and has 46 almost identical segments. Projecting from each is a delicate, gill-like structure. It would probably have looked like a bit like a horseshoe crab and the gills would have been for absorbing oxygen from the water it lived in. Its insides are exquisitely well-preserved, which is very unusual for fossils – normally only the hard, more decay-resistant external features would be preserved. You can see bundles of muscle fibres that would have powered the limbs, tendons and an internal scaffold structure that gave the animal rigidity. We think it would have spent most of its life living on, or more likely just above, the seafloor, probably walking and swimming in an undulatory (waving) motion. It lived in the immediate aftermath of the end Ordovician extinction event more than 440 million years ago, caused by glaciations (the spread of icy conditions) across vast swaths of the planet. This extinction wiped out about 85% of Earth's species. The marine basin that Keurbos susanae inhabited was probably very cold and at times covered with sea ice. It was a relatively hostile environment in other ways too. Our analyses of the chemistry of the shales – the sediments on the sea bed where this animal and others lived, now turned to rock – shows that they were deposited under anoxic conditions (that is, there was no oxygen circulating freely in the water). And at times free hydrogen sulfide occurred in the sediment porewaters (the water in tiny spaces between grains of sediment) and even above the seafloor. Not much could live in these conditions and this was critical to this fossil's amazing preservation. It meant the carcass was not scavenged by other animals after it died. Also, the chemistry was important in the process whereby the soft tissues, which should usually rot away rapidly, became mineralised quickly after death. This turned the animal's anatomy to mineral which survived for hundreds of millions of years until it was discovered. It is preserved 'inside out'. Keurbos susanae is a new genus and species which we are still trying to place among other early arthropods. The fact that its insides are better preserved than its outside makes it difficult to compare with other fossils that are preserved the 'other way round'. How did you find the fossil and what else has been found in that area? The site is in the Cedarberg mountains, north of Cape Town. To collect fossils in this area you need a permit granted by the Council for Geoscience. Fossil-bearing rocks are protected by law because of their heritage and scientific value. Fossil hunting in these rocks takes a lot of hard work and patience, splitting open the shales with a hammer and chisel. These shale rocks are what's left of layers of silt that were once on the sea floor. The fossils here are super rare: you can dig and split shale for days and not find a single fossil! But we know there are some in there because of discoveries made previously. I found two specimens. The first one is complete but the second one only has the middle part of the body preserved. In the same rocks we have found some of the earliest vertebrate fossils with mineralised teeth, called conodonts. They were eel shaped and predatory. Also eurypterids (sea scorpions), arthropods with powerful swimming appendages, which would have cruised through the frigid waters. There are also orthocones – a type of chambered cephalopod – like the mollusc fossils called ammonites, which have been found in large numbers, but with a straight shell instead of coiled. Why has it taken 25 years to describe Keurbos susanae scientifically? Two reasons really. First, because of the nature of preservation, where all the insides are perfectly preserved but the outside (the carapace or body covering) is absent, it is just difficult to interpret and compare to other fossils. And secondly because the specimen's head and legs are missing and these are key characteristics that palaeontologists would use to help them to understand the evolutionary relationships of such fossils. If more specimens were to be found, with their heads and legs, we could be more certain about where this fossil fitted in the scheme of life. But the site where I found it has been covered in a lot of rock from quarrying activity. So we decided to describe what we had in the meantime, and not wait for more examples. The fossil's name, Keurbos susanae, refers to the place where I found it and to my mother, Sue, who encouraged me to follow a career that made me happy, whatever that might be. This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Sarah Gabbott, University of Leicester Read more: Sarah Gabbott receives funding from Natural Environmental Research Council; National Geographic. She is affiliated with Green Circle Nature Regeneration CIC a not for profit Environmental Community Interest Company in the UK
Yahoo
31-03-2025
- Science
- Yahoo
Scientists discover 'legless, headless wonder' that predated the dinosaurs
Paleontologists are marveling over the unique fossil of a marine species that predated the dinosaurs, according to new research. The fossil, dated to about 444 million years ago, contained a new species of arthropod that fossilized inside-out, earning the description of a "legless, headless wonder," according to a paper published in the journal Palaeontology last week. MORE: Ancient parasitic 'Venus flytrap' wasp found preserved in amber The "exceptionally preserved" euarthropod was found with its muscles, sinews, tendons and guts all preserved in "unimaginable detail," said Sarah Gabbott, a professor at the University of Leicester's school of geology and lead author of the paper, said in a statement. "Remarkably her insides are a mineralised time-capsule," Gabbott said, adding that the specimen's head and legs were lost to decay over hundreds of millions of years. The new species was dubbed "Keurbos susanae," or "Sue" -- after the mother of the woman who discovered it. Researchers are certain it is primitive marine arthropod, but the precise evolutionary relationships remains "frustratingly elusive," Gabbott said. The fossil was located on Soom Shale, a band of silts and clays about 250 miles north of Cape Town, South Africa. At the time the strata was laid down, a "devastating" glaciation had wiped out about 85% of Earth's species -- one of the "big five" mass extinctions in Earth's history, the researchers said. MORE: What scientists learned from a well-preserved fossil of this iconic Jurassic-era species But the marine basin where Sue was found was somehow protected from the worst of the freezing conditions and provided shelter for a community of "fascinating" species, according to the paper. "This fossil is just so beautifully preserved there's so much anatomy there that needs interpreting," Gabbott said. "Layer upon on layer of exquisite detail and complexity." The sediments that trapped the specimen were extremely toxic, the researchers said. The water contained no oxygen, but hydrogen sulphide -- described as not only "stinky" but deadly -- was dissolved in the water, the researchers said. An unusual chemical alchemy may have been responsible for the unique way Sue was fossilized, the researchers hypothesized. About 85% of the animals on Earth today are arthropods -- including shrimps, lobsters, spiders, mites, millipedes and centipedes, the paper states. MORE: How the process of de-extinction will be used to restore this fabled species The downside to Sue's unique fossilization is it makes it hard to compare the specimen with other fossils of similar species of the time. "So it remains a mystery how she fits into the evolutionary tree of life," according to the researchers. Scientists discover 'legless, headless wonder' that predated the dinosaurs originally appeared on
Yahoo
29-03-2025
- Science
- Yahoo
Scientists uncover 'inside-out, legless, headless wonder' that lived long before the dinosaurs
When you buy through links on our articles, Future and its syndication partners may earn a commission. Scientists have found two specimens of a 444 million-year-old "inside-out" fossil with well-preserved soft tissue, according to a new study. Unlike most fossils, the creature's muscles and guts — but not its more durable shell — are preserved in ancient sediment that turned to stone. The fossil, found 250 miles (402 kilometers) north of Cape Town in South Africa, is a new species of multisegmented arthropod that may have lived in oxygen-poor waters, according to the study, published March 26 in the journal Papers in Palaeontology. Researchers named the new species Keurbos susanae and nicknamed the fossil "Sue" after its discoverer's mom. "Sue is an inside-out, legless, headless wonder," lead author Sarah Gabbott, a paleontologist at the University of Leicester in the U.K., said in a statement. "Remarkably, her insides are a mineralized time-capsule: muscles, sinews, tendons and even guts all preserved in unimaginable detail. And yet her durable carapace, legs and head are missing — lost to decay over 440 million years ago." The researchers found the fossils in the Soom Shale, a site known for producing fossils with well-preserved soft tissues, more than 20 years ago. They had hoped to find additional specimens, but fossils of the species turned out to be quite rare. The silt, clay, and mud in which Sue was preserved were deposited on an ancient seafloor, beneath an ocean low in oxygen but high in dissolved, acidic hydrogen sulfide — suggesting that K. susanae may have been adapted for a low-oxygen environment. Sue dates back to the Late Ordovician mass extinction (443 million years ago), when cold temperatures and glacier advancement eliminated nearly 85% of marine species. Researchers are still working to understand how soft tissues in fossils like K. susanae are preserved in the Soom Shale. Clay minerals may have played a role, as could calcium phosphate, a compound commonly found in fossilized muscles. On the other hand, the shells and exoskeletons of species preserved in Soom Shale likely dissolved in the acidic ocean. Because the K. susanae specimen was fossilized inside out, scientists still aren't sure of the species' evolutionary history or how it compares to other fossils from the same time period. "We are now sure she was a primitive marine arthropod, but her precise evolutionary relationships remain frustratingly elusive," Gabbott said in the statement. The fossil's segmented trunk suggests it had limbs of some kind — but comparing Sue to known fossil species would require a sample with part of the exoskeleton preserved. RELATED STORIES —Sponges Ruled the World After Second-Largest Mass Extinction —Rare fossils reveal basketball-like skin on duck-billed dinosaur —Ravenous meat-eating dinosaur's guts preserved in exceptionally rare fossil Recent quarrying activity has buried the site where Gabbott and her colleagues found Sue, so it's unlikely they'll find other examples of the same species with intact legs or a head, the team said. "I'd always hoped to find new specimens, but it seems after 25 years of searching this fossil is vanishingly rare — so I can hang on no longer," Gabbott said. "Especially as recently my mum said to me, 'Sarah, if you are going to name this fossil after me, you'd better get on and do it before I am in the ground and fossilized myself'." Gabbott joked that she named the fossil after her mom because she's a "well-preserved specimen." But the true reason, she said, is that "my mum always said I should follow a career that makes me happy — whatever that may be. For me that is digging rocks, finding fossils and then trying to figure out how they lived what they tell us about ancient life and evolution on Earth."
