Latest news with #Ordovician
Time of India
22-05-2025
- Science
- Time of India
The secret history of teeth revealed: How they originated inside a 465-million-year-old fish's body
Our knowledge about the origins of teeth pertains to that of the entire body, a natural occurrence made up of tissues. But did you know that human teeth evolved from the "body armour" of an extinct fish that lived 465 million years ago? From vertebrates to teeth In a published in the journal Nature on Wednesday, researchers showed how sensory tissue discovered on the exoskeletons of ancient fish is linked to the same "genetic toolkit" that produces human teeth. Tired of too many ads? go ad free now "This shows us that 'teeth' can also be sensory even when they're not in the mouth," said Yara Haridy, co-author of the study and palaeontologist and evolutionary biologist at the University of Chicago. Initially, researchers set out to identify the earliest vertebrate in the fossil record seeking specimens from the Cambrian and Ordovician periods. An obvious sign of a vertebrate species is the presence of internal tubules for dentine, a calcified tissue that is found under the enamel in the human teeth, but also in the external bumps or odontodes in ancient fish armour. While making the use of high-resolution CT scans to analyse the jawless "first fish" species Anatolepis heintzi, the researchers discovered pores filled with dentine. They also compared the fossil to a coterie of ancient fossils and modern marine life. The shocking discovery Upon closer investigations, researchers realised that the supposed dentine-lined pores were like the sensilla, the sensory organs on the shells of crabs, thus making A. Heintz, an ancient invertebrate arthropod and not a vertebrate fish. Vertebrates and invertebrates, both have sensory armours connected to nerves that help them sense their environment. To substantiate the discovery that the fish was an arthropod, the team scanned fossils and modern specimens from snails and barnacles to sharks and catfish. It was revealed that the suckermouth catfish raised in Hardy's own lab had small tooth-like scales on their skin, called denticles, that were connected to nerves. Tired of too many ads? go ad free now This discovery also led to the realisation that ancient vertebrates had the same mineralized tissue that evolved into dentine and then our sensitive teeth. These tissues helped them sense their environment like cold waters or pressure from nearby objects, just like our teeth. Thus, this study also supports a key theory in evolutionary biology called the "outside-in" hypothesis where sensory structures evolved on exoskeletons at least 460 million years ago and were used by animals to make teeth. "Viewed through this evolutionary lens, the fact that teeth in the mouth are extremely sensitive is less of a mystery, and more a reflection of their evolutionary origins within the sensory armour of early vertebrates," wrote the researchers in the study.
Yahoo
22-05-2025
- Science
- Yahoo
Tooth pain's origins traced to 465-million-year-old armored fish with sensors
Ever wonder why teeth hurt? Blame it on a prehistoric armored the outer layer of our teeth is coated in hard enamel, it's the inner layer, called dentine, that feels pain. Dentine carries signals to the nerves when we bite into something hard, or feel the sting of ice cream or sweetness. Scientists have long debated where teeth came from. One idea was that they evolved from small bumps on the tough outer shells of ancient fish. These bumps, known as odontodes, were once a mystery. But now, a new study confirms that these structures in an early vertebrate fish from the Ordovician period, about 465 million years ago, contained dentine. Using 3D scans on fossils of the fish, researchers discovered that these bumps were sensitive and were likely used to sense their environment, like detecting cold water or pressure from nearby objects. While studying the fossils, the team also found that odontodes in ancient fish looked a lot like sensilla — tiny sensory organs found in the shells of animals like crabs and shrimp. Sensilla are also seen in fossils of ancient invertebrates. Surprisingly, these two features evolved in completely different animal groups: fish, which have backbones, and arthropods, which don't. According to Dr. Yara Haridy, who led the study, this is a classic case of evolutionary convergence — when different species develop similar traits on their own. 'These jawless fish and Aglaspidid arthropods (extinct marine arthropods) have an extremely distant shared common ancestor that likely had no hard parts at all,' Haridy said. 'We know that vertebrates and arthropods evolved hard parts independently and amazingly they evolved similar sensory mechanisms integrated into their hard skeleton independently.' The findings also help explain a long-standing mix-up in the fossil record. For decades, a Cambrian-era fossil called Anatolepis was thought to be one of the earliest vertebrates, thanks to tooth-like bumps on its surface. But when the researchers closely examined the fossil using high-resolution CT scans, they realized those bumps didn't contain dentine after all. Instead, they looked just like the sensory structures — sensilla — seen in arthropods. That meant Anatolepis wasn't a vertebrate fish, but likely an ancient arthropod. The confusion, it turns out, is understandable. Sensory armor evolved in both vertebrates and invertebrates, and it often looks strikingly similar under the microscope. That's because both groups developed ways to sense their environment using nerve-connected structures embedded in hard outer coverings — whether it was fish skin or crab shell. To compare these features more broadly, the team scanned fossils and modern specimens ranging from snails and barnacles to sharks and catfish. One discovery stood out: suckermouth catfish raised in Haridy's own lab had small tooth-like scales on their skin — called denticles — that were directly connected to nerves. These denticles, like the ancient odontodes and arthropod sensilla, weren't just armor — they were sensory tools. 'We think that the earliest vertebrates, these big, armored fish, had very similar structures,' Haridy said. 'They look the same in ancient and modern arthropods because they're all making this mineralized layer that caps their soft tissue and helps them sense the environment.' This research also adds weight to a key theory in evolutionary biology. Called the "outside-in" hypothesis, the theory suggests that teeth evolved from external sensory structures like these. In other words, long before animals had mouths full of teeth, they had sensitive armor that helped them survive. While they didn't pin down the earliest vertebrate fish, Neil Shubin, the senior author of the study, said this discovery was more than worth the effort. 'For some of these fossils that were putative early vertebrates, we showed that they're not. But that was a bit of misdirection,' he said. 'We didn't find the earliest one, but in some ways, we found something way cooler.' The study has been published in the journal Nature.
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
02-05-2025
- Business
- Yahoo
American Salars Lithium to acquire Cauchari Lithium Salar project in Argentina
Public exploration company American Salars Lithium has signed a letter of intent (LOI) with an arm's-length vendor to acquire a 100% stake in the Cauchari Minas Ines 01 Lithium Salar project in Salta Province, Argentina. The project is a fully owned concession spanning 12km². The Cauchari Ines 01 claims cover approximately 1,235ha with lithium concentrations sampled up to 383 parts per million (ppm) lithium. The project is accessible via existing mining tracks and roads and is situated 13km from the Rincon salar owned by Rio Tinto. The area's infrastructure includes immediate proximity to roads, railroads, electricity and gas pipelines, enhancing the project's mining potential. American Salars CEO and director R. Nick Horsley said: 'The potential of this section of the Salar de Cauchari is immense. Cauchari is a proven producing Salar operated by Exar – Ganfeng & Lithium Argentina that produces battery grade lithium carbonate. The company will look to continue to increase its footprint on the Cauchari and Pocitos Lithium projects.' The geology of Cauchari is complex, featuring Ordovician sediments, tertiary sedimentary outcrops and tertiary vulcanites. Data from reconnaissance exploration programmes indicate that the Cauchari Salt Lake underlies a large, structurally controlled sedimentary basin that forms an aquifer of more than 250km². The basin is part of an endorreic system, with the Tocomar river as its main collector. The aquifer, potentially rich in lithium, has yet to have its effective porosity determined. In March 2025, American Salars Lithium signed an LOI with an arm's-length vendor to acquire up to 100% of the Salar De Pocitos project in Salta Province, Argentina, from Recharge Resources. American Salars has also announced that it has reached a settlement agreement with Ekeko concerning a lien placed on the Pocitos 1 project. This lien resulted from a payment deficit by Recharge Resources. The agreement involves a total of $200,000 (C$276,507) in cash payments for a full release of all liabilities against Recharge Resources, with payments due in May and September 2025. "American Salars Lithium to acquire Cauchari Lithium Salar project in Argentina" was originally created and published by Mining Technology, a GlobalData owned brand. The information on this site has been included in good faith for general informational purposes only. It is not intended to amount to advice on which you should rely, and we give no representation, warranty or guarantee, whether express or implied as to its accuracy or completeness. You must obtain professional or specialist advice before taking, or refraining from, any action on the basis of the content on our site. Sign in to access your portfolio
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?
