Latest news with #Keurbossusanae
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
15-04-2025
- Science
- Yahoo
Scientists Found a 444-Million-Year-Old Inside-Out Fossil With Its Guts Perfectly Intact
Discovered 25 years ago, a 444-million-year-old marine arthropod fossil stumped paleontologists, as they couldn't identify its exact species. Sarah Gabbot, who originally discovered the specimen, realized that the fossil had been preserved inside-out, meaning its muscles, tendons, and guts were exquisitely preserved while its limbs, carapace, and even head had dissolved away. Gabbot named the specimen Keurbos susanae—nickname 'Sue'—in honor of her mother, whom she said always supported her love of paleontology. Arthropods are the most successful animal group on the planet. These varying invertebrates make up roughly 85 percent of all animal life on the planet, and they have one of the most extensive and well-preserved fossil records of any animal group, with examples dating back some 518 million years ago to the Cambrian era—a.k.a. when complex life really boomed for the first time. Fast forward some 73 million years to the end of the next geologic period (the Ordovician), and life meets its first bust. The first of five (or possibly six) mass extinctions in Earth history, the Late Ordovician mass extinction wiped out roughly 85 percent of all life on Earth, making it the second most deadly (after the Permian extinction—you don't get the nickname 'The Great Dying' for nothing). It was during this tumultuous biological period, that a certain arthropod met its end, eventually becoming entombed and fossilized in Soom Shale—a band of silts and clays located 250 miles north of Cape Town, South Africa. Although intense glaciation laid waste to the planet, this small pocket of the world continued to thrive even under icy threat. Some 444 million years later, paleontologists unearthed this particular specimen, but it's appearance didn't match anything in the fossil record. That is, until Sarah Gabbott, a lead author on a study published in the journal Paleontology detailing this new species (named Keurbos susanae after the lead author's mother, Sue), made the surprising discovery—the fossil was actually preserved inside-out. ''Sue' is an inside-out, legless, headless wonder,' Gabbott said in a press statement. 'Remarkably her insides are a mineralised 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.' Although this fossil's resting place included an anoxic environment (a necessary ingredient for fossilization to occur), it also contained hydrogen sulphide dissolved in the water. The researchers believe this chemistry likely dissolved away the carapace. Yet the mineral that perfectly preserved the marine arthropods insides—calcium phosphate—is the same mineral found in our bones and teeth. Gabbott told IFLScience that she's still trying to work out the exact details of how this strange inside-out preservation took place. Although 'Sue'—not to be confused with another famous fossil of the T. Rex persuasion—provides an incredible glimpse at the organs and guts of an ancient arthropod, it's difficult to know where to place the specimen on the tree of life—even 25 years after Gabbott first discovered it. 'This has been an ultramarathon of a research effort,' Gabbott said in a press statement. 'In a large part because this fossil is just so beautifully preserved there's so much anatomy there that needs interpreting. Layer upon on layer of exquisite detail and complexity.' While the mystery remains, the naming of the species at least checks off one to-do on Gabbott's list: '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.'' You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
