Subscriber CaaC (John)+ Posted July 29, 2022 Author Subscriber Share Posted July 29, 2022 Quote Plesiosaur fossil found in Morocco shows the marine animals also lived in freshwater Some have said the find makes the Loch Ness monster myth “plausible”. If you’re like me, you are a facts-based science nerd with a penchant for the fun and mystery that surrounds cryptozoology and mythology. Even better is when the two worlds of science fact and mythology cross over. A new fossil discovery in Morocco has sent imaginations racing once again. One of the most famous cryptids (animals unknown to science but said to exist by those who claim to have seen them, or signs of them) is the fabled Loch Ness monster, or “Nessie”. Nessie is believed by some to live in the Scottish Highlands lake called Loch Ness. We could throw into the mix the animal known as “Champ” which is said to live in Lake Champlain which crosses the border between Canada and the north-eastern United States. While proof of Nessie and Champ’s existence remains elusive, for hundreds of years, visitors to the lakes have insisted they have seen the animals. Attempts to give scientific credence to the myths have included suggestions that Nessie and Champ may be the last vestiges of a by-gone age. First found and described in 1823 by palaeontologist Mary Anning, plesiosaurs are long-necked, small-headed, flippered marine reptiles which lived during the time of the dinosaurs. Their body shape matches the long neck, smooth, scaly skin, and undulating serpentine body ascribed to Nessie and Champ by alleged witnesses. It is extremely unlikely that a population of animals would have gone unnoticed and left no trace for 66 million years to the point of making this theory simply untenable. But, putting that to one side, there is another major problem: Both Lake Champlain and Loch Ness are freshwater lakes. See, plesiosaurs were marine reptiles, meaning that they lived exclusively in saltwater. That is, we thought they did. Until now. Scientists from the University of Bath and University of Portsmouth in the UK have published their findings of a new extinct plesiosaur in the journal Cretaceous Research. The plesiosaur fossils were discovered in the Kem Kem Geological Group in eastern Morocco near the border with Algeria. The Kem Kem is home to many famous discoveries including the massive carnivorous dinosaurs Carcharodontosaurus and Spinosaurus. One specimen is that of a 1.5-metre-long baby which lived 100 million years ago. The animal was found in what is now dry Morocco but would have been a river during the Cretaceous period. The fossils hint that the creatures lived and fed in freshwater alongside giant crocodiles and Spinosaurus which is thought to be aquatic. Not only does the find suggest that the plesiosaurs could tolerate freshwater, but that they may even have spent their lives there, the researchers say. Included among the fossils are neck, back and tail vertebrae, teeth, and a piece of the juvenile’s forelimb. “It’s scrappy stuff, but isolated bones actually tell us a lot about ancient ecosystems and animals in them. They’re so much more common than skeletons, they give you more information to work with” says corresponding author Dr Nick Longrich, a University of Bath palaeontologist. “The bones and teeth were found scattered and in different localities, not as a skeleton. So each bone and each tooth is a different animal. We have over a dozen animals in this collection.” Bones tell us where the animals died. But the heavily worn teeth were shed while the animals were still alive, hinting at the fact that the site is not just where they died, but where they lived as well. Modern marine animals like whales and dolphins sometimes wander into rivers to feed or because they are lost. But the number of plesiosaur fossils makes this an unlikely scenario for the Cretaceous animals. It is more likely that the plesiosaurs, more like beluga whales, are able to tolerate both fresh and salt water. The animals could even have been permanent freshwater inhabitants like some modern dolphins which have evolved to be freshwater specialists four times – in the Ganges River, the Yangtze River and twice in the Amazon. “We don’t really know why the plesiosaurs are in freshwater,” adds Longrich. “It’s a bit controversial, but who’s to say that because we palaeontologists have always called them ‘marine reptiles’, they had to live in the sea? Lots of marine lineages invaded freshwater.” The Moroccan plesiosaurs belong to the family Leptocleididae. These smaller plesiosaurs have been found around the world including in England, Africa and Australia. A diverse and adaptable group of animals, plesiosaurs swam Earth’s ancient oceans for over 100 million years. The scientists believe they may even have invaded freshwater to different degrees multiple times. “We don’t really know, honestly. That’s how paleontology works. People ask, how can paleontologists know anything for certain about the lives of animals that went extinct millions of years ago? The reality is, we can’t always. All we can do is make educated guesses based on the information we have. We’ll find more fossils. Maybe they’ll confirm those guesses. Maybe not,” says Longrich. The researchers say that the new discovery increases the diversity of Cretaceous Morroco. “This is another sensational discovery that adds to the many discoveries we have made in the Kem Kem over the past fifteen years of work in this region of Morocco,” explains team member and co-author Samir Zouhri of the Moroccan Hassan II University of Casablanca. “Kem Kem was truly an incredible biodiversity hotspot in the Cretaceous.” “What amazes me” says co-author Dave Martill, “is that the ancient Moroccan river contained so many carnivores all living alongside each other. This was no place to go for a swim.” So, it is plausible that Nessie and Champ are real and that they are freshwater plesiosaurs. But don’t hold your breath. As much as we want to believe, this fact-hardened author agrees with scientific consensus that plesiosaurs died out with large dinosaurs 66 million years ago. https://cosmosmagazine.com/history/morocco-plesiosaur-fossil-loch-ness/ Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted August 6, 2022 Author Subscriber Share Posted August 6, 2022 (edited) Quote Neanderthal vs. modern humans: Slow and steady wins the brain game Small genetic changes separate modern humans from ancestral brain development. Our closest human relatives are Neanderthals (split from modern humans at least 500,000 years ago) and their Asian relatives the Denisovans (split from modern humans around 800,000 years ago). The differences between Homo sapiens and these other groups are encoded in changes to the amino acids which are the building blocks of proteins in our cells and tissues. About 100 amino acids changed in modern humans after these splits and spread throughout almost all of us. The biological significance of these changes, however, is largely unknown. Researchers in Germany looked at changes to six of these amino acids occurring in three proteins. These amino acids play key roles in the distribution of chromosomes to the two daughter cells during cell division. Since the remarkable work done in sequencing the Neanderthal genome this study furthers our understanding of the subtle differences between these ancient humans and modern humans. It may also shed some light on the evolutionary advantages that eventually saw modern humans outlive Neanderthals and Denisovans. Authored by researchers from the Max Planck Institute for Evolutionary Anthropology in, the results are published in Science Advances. To investigate how these six changes impact brain development, the scientists introduced the amino acids from modern human variants into mice. Interestingly, in those six amino acid positions, mice are identical to Neanderthals. That makes mice brains perfect for testing what happens when these amino acids are changed. Lead author of the study, Felipe Mora-Bermúdez, says the changes result in more accurate transfer of genetic data in cell division. “We found that three modern human amino acids in two of the proteins cause a longer metaphase, a phase where chromosomes are prepared for cell division, and this results in fewer errors when the chromosomes are distributed to the daughter cells of the neural stem cells, just like in modern humans.” The team also checked to see if the opposite would be true. If they replaced the modern human amino acids with those present in Neanderthals, would they see faster and less accurate mitosis? They introduced the ancestral amino acids in human brain organoids. Organoids are miniature organ-like structures that can be grown from human stem cells in the lab which mimic aspects of early human brain development. “In this case, the metaphase became shorter and we found more chromosome distribution errors.” According to Mora-Bermúdez, this shows that those three modern human amino acid changes in the proteins are responsible for the fewer chromosome distribution mistakes seen in modern humans compared to Neanderthal and chimpanzees. He adds that “having mistakes in the number of chromosomes is usually not a good idea for cells, as can be seen in disorders like trisomies and cancer.” “Our study implies that some aspects of modern human brain evolution and function may be independent of brain size since Neanderthals and modern humans have similar-sized brains. The findings also suggest that brain function in Neanderthals may have been more affected by chromosome errors than that of modern humans,” adds co-author Wieland Huttner. Svante Pääbo, who also co-supervised the study, adds that “future studies are needed to investigate whether the decreased error rate affects modern human traits related to brain function.” https://cosmosmagazine.com/history/neanderthal-human-brain-development/ Edited August 6, 2022 by CaaC (John) Spacing correction Quote Link to comment Share on other sites More sharing options...
MUFC Posted August 9, 2022 Share Posted August 9, 2022 Quote Link to comment Share on other sites More sharing options...
Spike Posted August 9, 2022 Share Posted August 9, 2022 On 15/07/2022 at 12:43, CaaC (John) said: Winton is so remote, but it is literally a dinosaur graveyard. They just keep finding stuff out there 1 Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted August 11, 2022 Author Subscriber Share Posted August 11, 2022 (edited) Quote Ancient insect calls for update to Jurassic Park soundtrack Scientists reconstruct the singing tones of a long-extinct katydid from a single specimen. For the past 150 years, the single known specimen of a species of katydid-like insect known as Prophalangopsis obscura has sat quietly in the London Natural History Museum but now some scientists have worked out what it would have sounded like. A British/Austrian team, used some seriously fancy equipment and an understanding of the physics of insect acoustics to work out what this species would have sounded like when it sang for a mate, giving insight into the ancient insect soundscape of the Jurassic period. Katydids are grasshoppers and crickets. This holotype, or single known specimen, is one of only eight remaining species from the 90 or so which were abundant during the Jurassic period. The research team has shown the sounds produced by this particular insect would have been similar to, although distinguishable from, other related species around this period. The chirp produced by P. obscura is a pure tone, emitted at around 4.7 kHz — well-within the range of human hearing. Aside from helping researchers understand what the insect world sounded like when dinosaurs roamed the Earth some 145 to 201 million years ago, the findings also suggest that early insects of this type were limited to frequencies below 20 kHz. This is important because the other species of Prophalangopsis known today have evolved to be flightless, using their wings exclusively for sound production and attracting a mate. These evolved species have also developed ultrasonic sound production organs to assist in deterring ground-based predators. Adult Angle-winged Katydid. Katydids in existence today tend to be flightless and capable of ultrasound. Credit: ViniSouza128/GettyBut, how do you hear an insect that has been dead for 150 years? Like katydids and their relatives, P. obscura, produced sound by scraping one of its wings with a ‘file’ (or row of teeth). These vibrations would then by amplified by special structures within the insect’s wing and radiated out into the surrounding environment. Scientists at the University of Lincoln, the Natural History Museum, London, UK and Karl-Franzens-University, Graz, Austria used a technique called micro-scanning Laser-Doppler Vibrometry (LDV) to scan and then reconstruct the wings and sound-producing organs of the holotype. They then applied knowledge of close relatives of the species, they were then able to infer the “carrier frequency” (the central frequency at which the overall sound reaches its maximum energy). Due to its low frequency and pure tone, the song P. obscura sang may have reverberated far and wide across the Jurassic landscape. https://cosmosmagazine.com/science/biology/ancient-insect-jurassic-sound/ Edited August 11, 2022 by CaaC (John) Spacing correction Quote Link to comment Share on other sites More sharing options...
MUFC Posted August 12, 2022 Share Posted August 12, 2022 Crazy!!! Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted August 13, 2022 Author Subscriber Share Posted August 13, 2022 Quote Breathe in, breathe out and thank your lucky… rocks? Geological processes responsible for life-giving oxygen came a billion years before photosynthesis. The Earth’s atmosphere is relatively rich in oxygen but the prevailing wisdom that much of it came from plants and bacteria, might not be entirely correct. The advent of photosynthesis — the production of energy and oxygen from carbon dioxide and light — by cyanobacteria had a big influence on the evolution of life and multi-cellular organisms in particular. However, a new study in Nature Communications suggests that hydrogen peroxide (an easy source of oxygen to microbes) was produced in substantial quantities much earlier in the Earth’s history, raising interesting questions about the early evolution of life (and perhaps the origins of life, more generally). Earth’s surface is not static and in particularly active tectonic regions, stresses build in the crust which are released through earthquakes and faulting activity. This produces defects or imperfections in the rocks below the surface which are then exposed to water filtering down from above. Jordan Stone, a master’s student at Newcastle University, simulated early rock defect conditions in the Earth’s oceanic and continental crust by crushing granite, basalt and peridotite, and then he exposed them to water in an oxygen-free environment. At temperatures close to the boiling point of water, Stone found that a substantial amount of hydrogen peroxide was produced from the crushed rocks. The high temperature range is a key discovery, says Stone. “While previous research has suggested small amounts of hydrogen peroxide and other oxidants can be formed by stressing or crushing rocks in the absence of oxygen, this is the first study to show the vital importance of hot temperatures in maximising hydrogen peroxide generation.” Heat-loving microbes, or hyperthermophiles, are incredibly resilient, growing best in temperatures above 80°C and surviving in temperatures beyond the boiling point of water (100°C). What’s more, they have ancient origins, lying near the root of the Universal Tree of Life and predating the emergence of photosynthesis. This is interesting to note as these oxygen-loving hyperthermophiles thrive in temperatures across the range of optimal hydrogen peroxide production and Stone’s research suggests that oxygen may have played a far more important role in the evolution of life before photosynthesis came along. https://cosmosmagazine.com/earth/oxygen-thank-your-lucky-rocks/ Quote Link to comment Share on other sites More sharing options...
MUFC Posted August 14, 2022 Share Posted August 14, 2022 Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted August 14, 2022 Author Subscriber Share Posted August 14, 2022 (edited) Quote A dino feat: How Littlefoot’s feet could have supported such massive dinosaur bodies New research into the biomechanics of sauropod feet answers a prehistoric question. As a child, any millennial remotely interested in dinosaurs (how many of us weren’t, really?) would have grown up with “longneck” Littlefoot and his friends in The Land Before Time. Sidestepping for a moment the years of emotional trauma caused by that scene (if you know, you know), Littlefoot’s name leads to a very apposite question. How did Littlefoot’s Apatosaurus family and other massive sauropod dinosaurs carry their colossal weight on their feet? Sauropods were not only the largest of the dinosaurs, the long-necked, small-headed behemoths were the largest land animals of all time. The largest like Dreadnoughtus and Argentinosaurus are estimated to have grown to 30 or 40 metres in length and weighed in at anywhere between 50-100 tonnes. The biomechanics of lugging all that weight around on land is no mean feat and palaeontologists have been scratching their heads about it for years. In fact, it has led many palaeontologists in the past to suggest that the only way sauropods could have carried their own weight around is if they were semi-aquatic animals with their weight supported by water. This theory was disproved in the mid-20th century by the discovery of fossilised sauropod tracks that were laid down on prehistoric land. Research from University of Queensland (UQ) and Monash University might have cracked the case using 3D modelling and engineering methods to reconstruct and test the foot structures of different sauropods. The team’s findings are published in Science Advances. Leading the research as part of his PhD at UQ, Dr Andreas Jannel says the results show sauropods evolved a soft tissue “pad” beneath the heels on their hind feet. This pad would have cushioned the foot to absorb their immense weight. The difference between elephant and sauropod feet is dueto their very different evolutionary paths according to the researchers. “Elephants belong to an ancient order of mammals called proboscideans, which first appeared in Africa roughly 60 million years ago as small, nondescript herbivores,” says co-author Steve Salisbury, associate professor at UQ. “In contrast, sauropods – whose ancestors first appeared 230 million years ago – are more closely related to birds. They were agile, two-legged herbivores and it was only later in their evolution that they walked on all fours. Crucially, the transition to becoming the largest land animals to walk the earth seems to have involved the adaptation of a heel pad.” As technology develops, a lot more palaeontology is being done through scans and computer simulations. This allows scientists to not only look at the fossilised remains of animals which lived tens of millions of years ago, but also make even more discoveries about how they lived. The 3D-modelling techniques used in the sauropod foot study are applicable to other areas of palaeontological research. “I’m keen to apply a similar method to an entire limb and to include additional soft tissue such as muscles, which are rarely preserved in fossils,” Jannel says. “We’re also excited to study the limbs and feet of other prehistoric animals. This should allow us to answer different questions about the biomechanics of extinct animals and better understand their environmental adaptations, movement and lifestyle.” https://cosmosmagazine.com/history/sauropod-feet-3d-model/ Edited August 14, 2022 by CaaC (John) Spacing correction Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted August 16, 2022 Author Subscriber Share Posted August 16, 2022 Quote The biggest Christian hoaxes of all time There are many examples of hoaxes throughout history. These range from basic, almost funny attempts of deception, to others that are indeed quite elaborate. But things can get even more interesting when we add religion into the mix; more specifically, Christianity. Over centuries, there have been numerous Christian hoaxes, and in this gallery we bring you some of the most impactful. Click through and get to know the biggest Christian hoaxes of all time. 1/31 PHOTOS - CLICK Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted August 17, 2022 Author Subscriber Share Posted August 17, 2022 Quote Impact crater may be dinosaur killer's baby cousin When an asteroid slammed into what is now the Gulf of Mexico 66 million years ago, wiping out the dinosaurs, did it have a companion? Was Earth bombarded on that terrible day by more than one space rock? The discovery of what seems to be a second impact crater on the other side of the Atlantic, of a very similar age, is raising these questions. It's not as big as the one we know at Chicxulub in Mexico, but still it speaks to a catastrophic event. Dubbed Nadir Crater, the new feature sits more than 300m below the seabed, some 400km off the coast of Guinea, west Africa. With a diameter of 8.5km, it's likely the asteroid that created it was a little under half a kilometre across. The day the dinosaurs' world fell apart Immense crater hole created in Tonga volcano Asteroid-strike dinosaur fossil found - scientists The hidden depression was identified by Dr Uisdean Nicholson from Heriot-Watt University, Edinburgh, UK. He'd been analysing seismic survey data, looking for somewhere to drill, to better understand past climatic changes on Earth. Such surveys, frequently obtained by oil and gas prospectors, record the different layers of rock and sediment underground, often to a depth of several kilometres. "These surveys are kind of like an ultrasound of Earth. I've spent probably the last 20 years interpreting them, but I've never seen anything like this," he told BBC News. "Nadir's shape is diagnostic of an asteroid impact. It's got a raised rim surrounding a central uplift area, and then layers of debris that extend outwards." The asteroid that created the Chicxulub Crater in the Gulf of Mexico is estimated to have been about 12km across. It gouged out a 200km-wide depression, and in the process set off mighty earth tremors, tsunamis, and a global firestorm. So much dusty material was thrown into the sky that Earth was plunged into a deep freeze. The dinosaurs couldn't ride out the climate shock. By comparison, the effects from a Nadir-sized impactor would have been much smaller. "Our simulations suggest this crater was caused by the collision of a 400m-wide asteroid in 500-800m of water," explained Dr Veronica Bray from the University of Arizona, US. "This would have generated a tsunami over one kilometre high, as well as an earthquake of Magnitude 6.5 or so. "The energy released would have been around 1,000 times greater than that from the January 2022 eruption and tsunami in Tonga." A 12km-wide object dug a hole some 100km across and 30km deep This bowl then collapsed, leaving a crater 200km across and a few km deep Today, much of the crater is buried offshore, under 600m of sediments On land, it is covered by limestone, but its rim is traced by sinkholes Scientists recently drilled into the crater to learn about its formation Dr Nicholson's team has to be cautious about tying the two impacts together. Nadir has been given a very similar date to Chicxulub based on an analysis of fossils of known age that were drilled from a nearby borehole. But to make a definitive statement, rocks in the crater itself would need to be pulled up and examined. This would also confirm Nadir is indeed an asteroid impact structure and not some other, unrelated feature caused by, for example, ancient volcanism. The idea that Earth may have been hit by a cluster of large space rocks in the past is not a new one. And people have already speculated that the impactor that created Boltysh Crater in Ukraine may also be related to the Chicxulub event in some way. Its age is not too dissimilar. Prof Sean Gulick, who co-led the recent project to drill into the Chicxulub Crater, said Nadir might have fallen to Earth on the same day. Or it might have struck the planet a million or two years either side of the Mexican cataclysm. Scientists will only know for sure when rocks from the west African crater are inspected in the lab "A much smaller cousin, or sister, doesn't necessarily add to what we know about the dinosaurs' extinction, but it does add to our understanding of the astronomical event that was Chicxulub," the University of Texas at Austin researcher told BBC News. "Was this a break-up of a parent body that had multiple fragments that hit Earth over time? Was Chicxulub a double asteroid where a smaller object orbited a bigger one? "These are interesting questions to pursue, because to learn that Chicxulub might have this extra excitement of a second crater at the same time changes the story a little bit about how Chicxulub came to be." The Nadir Crater feature is reported in the journal Science Advances. https://www.bbc.co.uk/news/science-environment-62575581 Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted August 19, 2022 Author Subscriber Share Posted August 19, 2022 (edited) Quote For those who like to rock: The most interesting rock formations on the planet Take a look at a staggering variety of weird rocks from around the world. Think of a rock. It’s angular, grey and on the ground, right? Wrong. Rocks come in a staggering variety of shapes and colours, which help us decipher the stories of their geological lives. Here are just a few of the fantastic rock formations found on this planet… Ah-Shi-Sle-Pah, New Mexico, USA “The Ah-Shi-Sle-Pah Wilderness can feel like an alien planet, with its strange shapes, colours and lack of vegetation,” says Stan Allison, of the Bureau of Land Management Farmington Field Office. The hoodoos – irregular columns of rock – dotted around the landscape also help create that otherworldly quality. Hoodoos are a lesson in differential erosion: the stronger sandstone resists the erosion that acts on the softer surrounding rock to create spires and precariously balanced capstones. Elsewhere, the ground is so soft that rain cuts vertical sinkholes into hills, carving mazes of ravines and gullies. MORE Edited August 19, 2022 by CaaC (John) Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted August 20, 2022 Author Subscriber Share Posted August 20, 2022 (edited) Quote 3D modelling shows megalodon could have swallowed prey the size of killer whales whole The reconstructed megalodon was 16 metres long and weighed over 61 tons. T. rex might have ruled the land but megalodon ruled the seas. A recent study led by scientists at the University of Zurich looked at the eating abilities of megalodon – and the results are frightening. Whether it be T. rex or megalodon, we’re fascinated by big, bad apex predators from prehistory – and just how big and bad they are. The largest predatory shark and biggest fish ever, megalodon ruled the seas until around three million years ago. Its exact dimensions are unknown since the cartilage that makes up shark skeletons don’t fossilise very well. Based on the animal’s teeth – and comparing them with its modern relative, the great white shark – it’s estimated that megalodon would have been 15-18 metres long which is three to four times the size of the biggest great whites today. A bus is about 13 metres long. A semi-trailer about 19 metres. Despite all the odds, a megalodon discovered in the 1860s did include a sizeable portion of the animal’s fossilised spine. Researchers believe the shark died when it was about 46 years old. It was found in the ocean which covered Belgium about 18 million years ago. So, the team of researchers went to work building a 3D model of the megalodon based on the find. Their results are published in the journal Science Advances. With researchers from Switzerland, UK, USA, Australia and South Africa, the team first measured and scanned every single vertebra, before reconstructing the entire column. Adding the column to a scan of a megalodon jaw from the US, they completed the model by adding “flesh” around the skeleton using a 3D-scan of a great white shark. “Weight is one of the most important traits of any animal. For extinct animals we can estimate the body mass with modern 3D digital modelling methods and then establish the relationship between mass and other biological properties such as speed and energy usage,” says co-author John Hutchinson, professor at the Royal Veterinary College in the UK. Their model provides a look at how the animal may have sized up in life. The reconstructed megalodon was 16 metres long and weighed more than 61 tons. The researchers estimate it could swim at around 1.4 meters per second and would have required over 98,000 kilocalories every day to meet its energy demands. With a stomach volume of almost 10,000 litres, the results suggest that the megalodon was capable of eating prey up to 8 meters long – whole! This means that today’s top ocean predator, the killer whale, could have been eaten whole by this ancient sea monster. Megalodon’s high demand for energy would have been met by feeding on calorie-rich whale blubber. Indeed, megalodon bite marks have previously been found in fossilised whale bones. Based on their model, the team found that eating a single eight-meter-long whale may have allowed the shark to swim thousands of kilometres without needing to eat again for two months. “These results suggest that this giant shark was a trans-oceanic super-apex predator,” says senior author Catalina Pimiento, professor at the University of Zurich. “The extinction of this iconic giant shark likely impacted global nutrient transport and released large cetaceans from a strong predatory pressure.” The team believes their model can now be used as a basis for future reconstructions and research to better understand how megalodon lived and the role it, as a super-apex predator, played in the ecosystem millions of years ago. https://cosmosmagazine.com/history/megalodon-ate-whales-whole/ Edited August 20, 2022 by CaaC (John) Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted August 23, 2022 Author Subscriber Share Posted August 23, 2022 (edited) Quote Giant Australian birds which lived alongside emus may have become extinct due to slow breeding patterns and belated sexual maturity Dromornis the “thunder bird” lived 7 million years ago and stood 3 metres tall. Slow breeding in giant Australian birds may have contributed to their extinction according to a new study of their fossils. Now extinct giant birds once roamed all around the world – often taking top spot as apex predator in their environment. Nowadays, the last of these large, flightless birds are a little more timid – like the third-largest living bird the emu and the largest, the ostrich. Research published in the Anatomical Record journal digs deeper into the mystery of why some of these giant feathered friends became extinct. Vertebrate palaeontologists from Flinders University and South Africa’s University of Cape Town looked at the microstructure of the huge birds’ fossil bones dug up in the Flinders Ranges near Alice Springs. Among Australia’s mihirung (the Aboriginal name for the giant dromornithids) were Dromornis stirtoni and Genyornis newtoni. Dromornis, or “thunder bird”, was the largest and oldest of the mihirung, living seven million years ago, standing up to three metres tall and weighing in at 600 kilograms. Dromornis stirtoni is arguably the largest ever bird to live on Earth. __________________________________________________________________________ Researchers looked at the impact of climate on 17-million-year-old tooth fossils. __________________________________________________________________________ By comparison, Genyornis newtoni was a “mere” 250 kilograms and stood two metres tall. The most recent of the mihirung, Genyornis would have lived alongside the earliest emus, dying out around 100,000 years ago. Studying the microstructure of the fossil bones the palaeontologists found the large size of these birds and their breeding cycle couldn’t keep pace with environmental changes. “Sadly for these amazing animals, which already faced rising challenges of climate change as the interior of Australia became hotter and dryer, their breeding biology and size couldn’t match the more rapid breeding cycle of modern day emus which were able to keep pace with the more demanding environmental conditions,” says Professor Anusuya Chinsamy-Turan, from the University of Cape Town. “Questions, such as how long these gigantic birds took to reach adult size and sexual maturity, are key to understanding their evolutionary success and their ultimate failure to survive alongside humans,” Chinsamy-Turan adds. “We studied thin sections of the fossilised bones of these thunder birds under the microscope so we could identify the biological signals recorded within. The microscopic structure of their bones gives us information about how long they took to reach adult size, when they reached sexual maturity, and we can even tell when the females were ovulating.” The study indicates that Dromornis stirtoni took a long time to become fully grown and reach sexual maturity – up to 15 years. Emerging later in the Pleistocene, when Australia’s climate had grown drier and more seasonal, Genyornis newtoni became sexually mature after only a couple of years. However, being six times as big as modern-day emus, they still took several more years to reach full adult body size. Co-author Trevor Worthy, associate professor at Flinders University, adds that mihirung lived alongside emus. “In fact, they persisted together through several major environmental and climatic perturbations,” he says. “However, while Genyornis was better adapted than its ancestors, and survived through two million years of the Pleistocene when arid and drought conditions were the norm, it was still a slow-growing and slow-breeding bird compared to the emu.” Despite the fossil record showing that late Pleistocene dromornithids’ reproductive biology had responded to climate pressures by breeding earlier in their lives, they just could not keep up with the changing environment or the reproductive efficiency of large birds which survived. Emu, for example, grow to full size and breed within 1-2 years. This allows the population to more effectively rebound after droughts and food scarcity. “The differing breeding strategies displayed by emus and dromornithids gave the emu a key advantage when the paths of these birds crossed with humans about 50 thousand years ago, with the last of the dromornithids goings extinct about 40 thousand years ago,” Worthy adds. “In the end, the mihirungs lost the evolutionary race, and an entire order of birds was lost from Australia, and the world.” https://cosmosmagazine.com/australia/thunder-bird-slow-breeding/ Edited August 23, 2022 by CaaC (John) Spacing correction Quote Link to comment Share on other sites More sharing options...
Subscriber nudge+ Posted August 24, 2022 Subscriber Share Posted August 24, 2022 Drought is not nice, but this is so cool! 1 Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted August 26, 2022 Author Subscriber Share Posted August 26, 2022 Quote Prehistoric burials gives insights into early human migration Three bodies found near Indonesian rock shelter at least 7,500 years old. Scientists have discovered three bodies on an Indonesian island which provide an insight into the movements of early humans, thousands of years ago. The bodies, found across three burial sites, form part of an excavation and analysis of 50,000 bones unearthed along the south coast of Indonesia’s Alor Island, which is north of Timor Leste. The various remains found beneath rock shelters in an area named Tron Bon Lei near Lerabain are between 7,500 and 13,000 years old. But it’s the way they were buried which provides unique insights into how early humans moved across Southeast Asia during the Pleistocene and Holocene periods. Studies are beginning to understand the genetic diversity of peoples within the region, which lead researcher Dr Samper Carro says can be further informed by the discovery of these bodies. “The three quite unusual and interesting burials show different mortuary practices,” Carro says. “They might relate to recent discoveries of multiple migratory routes through the islands of Wallacea from thousands of years ago. “It shows how burial practices can complement data on genetic diversity from one of the current research hotspots in Southeast Asia.” Burial practices and the talking dead The discovery of human remains in the region began in 2014, when teams from ANU and Indonesia’s Gadjah Mada University, found a 12,000-year-old human skull buried along with several fish hooks. More bodies were found when the team returned to the site four years later. Carro then spent several COVID-interrupted years studying the remains, with the results now published in PLOS One. It’s the positioning of the bodies beneath the surface which provides archaeologists with insights into the different cultures that migrate through the region. One of the bodies had its extremities intentionally removed before being buried. Another was placed in a ‘seated’ position, while the third was lying on its side. “Burials are a unique cultural manifestation to investigate waves of migration,” Carro explains. Burial practices can provide scientists with insights into migratory patterns carried out by ancient cultures. Equally, these practices may have developed locally, which is why Carro says further research to characterise mortuary practices in the region will help provide greater accuracy to her findings. “Further research in aspects such as biomolecular anthropology, diet practices, or the types of tools used in burial rites will allow us to gather more data,” she says. “These future efforts will provide us deeper insights to interpret the life ways of these communities.” https://cosmosmagazine.com/history/prehistoric-burials-migration-indonesia/ Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted August 27, 2022 Author Subscriber Share Posted August 27, 2022 Quote Oldest human ancestor may have been bipedal 7 million years ago Bipedalism may have developed much earlier than thought in human evolution. When in human evolution did the decisive step of bipedalism take place? There is no clear answer, but research from France suggests it was a lot earlier than many thought. Developing the ability to walk on two legs is regarded as critical in our evolution. Keeping our hands free while travelling allows us to carry tools. Walking upright and on two legs enabled our ancestors to make their way out of the shrinking forests of ancient Africa onto the open savannah because they would have been able to peer over the long grass to keep an eye out for predators. So, it would have been a giant leap for our ape-like ancestors. But so little fossil evidence remains from this part of the human journey that it is difficult to pinpoint the transition. A new study involving scientists from the French National Centre for Scientific Research (CNRS), University of Poitiers in France, and researchers from the central African country Chad, sheds some more light on when bipedalism evolved in early humans. The team examined the fossils of three limb bones from the oldest human representative known to science, Sahelanthropus tchadensis and have published findings in Nature. Discovered by the Franco-Chadian Paleoanthropological Mission (MPFT) in 2001, Sahelanthropus tchadensis dates back seven million years. Back then, changes in the climate saw Africa begin drying leading the continent’s forests to retreat, opening up its now iconic savannah grasslands. Massive elephant-like Stegotetrabelodon and Deinotherium, and long-clawed, strange relative of horses called Ancylotherium roamed these burgeoning plains. Other recognisable animals similar to modern hippos, giraffes and big cats all would have made early humans tread lightly. Included in the 2001 fossils of Sahelanthropus tchadensis was a remarkably well-preserved cranium. The orientation and position of the occipital foramen in the cranium (where the spine connects to the skull) indicated the animal was capable of bipedalism. In addition to the cranium the MPFT found jaw and tooth fragments, and two forearm bones and a femur. With no other large primate found at the site, these other fragments were attributed to Sahelanthropus tchadensis, though it is unclear if they are from the same individual, which was nicknamed Toumaï, meaning “hope of life” in the local central Saharan Gorane language. The femur and forearm bones were analysed and compared to modern and extinct apes, and members of the human group including ancient Homo sapiens, other ancestral Homo species, and australopithecines. According to the results of the forearm analyses, while climbing through the trees, Sahelanthropus tchadensis would have used a mixture of bipedal and quadrupedal locomotion enabled by firm hand grips. This is a marked divergence from the arboreal movement of gorillas and chimpanzees which lean on the back of their foot and hand bones. The authors write that the femur shows “habitual bipedality” would have been the most energy-efficient mode of transport for Sahelanthropus tchadensis while the forearms “preserve evidence of substantial arboreal behaviour.” “Taken together, these findings suggest that hominins were already bipeds at around 7 million years ago but also suggest that arboreal clambering was probably a significant part of their locomotor repertoire.” This study, in addition to earlier cranial studies of our oldest human ancestor Sahelanthropus tchadensis, suggests that bipedalism developed very early in our evolution. https://cosmosmagazine.com/history/bipedal-7mya-human-ancestor/ Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted August 29, 2022 Author Subscriber Share Posted August 29, 2022 Quote Absolute gem of a find: Opalised dinosaur fossil studied using innovative 3D printing technology The rare fossils may represent a new Australian dinosaur species. Palaeontologists at Adelaide’s Flinders University have used cutting edge micro-CT scanning and 3D printing technology to look inside a 100-million-year-old dinosaur fossil. But this was no ordinary fossil. In a rare find, collectors unearthed fossils of a small dinosaur which had opalised. They believe it might be a new species of Australian dinosaur. The dinosaur was a small bipedal herbivore called a hypsilophodont. The fossils were found in the opal mining town of Lightning Ridge, in outback New South Wales and were recovered and rescued for scientific study in 2019. A collaboration between the Australian Opal Centre at Lightning Ridge and the Palaeo Pictures documentary team led by Paul Willis, associate professor at Flinders University, will see the dinosaur reconstructed from the opalised fossils. Opals are formed when silicon dioxide dissolved in water trickles through the Earth until it reaches cavities in rocks. Once the water evaporates, a silica deposit is left behind. Sometimes, the cavities in which opals form are there because a living thing was buried in sand or clay before it hardened into stone. The opal forms in the mould leaving behind the fossil replica of the creature. Fossils found at Lightning Ridge are often colourless and “valueless” (monetarily speaking) potch. But occasionally the fossils are composed of precious opal – even the treasured black opal – and are very high in value. But Willis insists that all fossil specimens are “priceless” to science. His team has begun using the latest imaging technology to learn more about the animal that left the impressions behind. “We’re using the Flinders CT Scanning Facility at Tonsley to look inside lumps of rock that contain the remains of a small dinosaur,” says Willis. The scans show the fossil preserved in exquisite detail. “Not only do the scans allow us to better understand exactly what we have as a dinosaur skeleton, they will be an invaluable aid to the next stage of studying this specimen, by removing the surrounding rock. “Prior to using scans on specimens like this, the removal of surrounding rock was very much a case of ‘doing it blind’, feeling our way in to reveal the bones. Now we can do that with more confidence because we know where the rock stops and the bone starts.” Around 20% of the fossil specimens have been scanned so far. Once the rest are processed the team will work on a detailed study of the skeleton and produce, using 3D printing, as complete a reconstruction as possible from the puzzle pieces. The palaeontologists hope the reconstruction will reveal if this is indeed a new species of dinosaur, and they will then try to give “life” back to the fossils by learning about how the animal lived and died. https://cosmosmagazine.com/history/opalised-dinosaur-flinders-scan-3d/ Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted September 7, 2022 Author Subscriber Share Posted September 7, 2022 (edited) Quote Viking poo helps uncover 55,000-year-old relationship with an intestinal parasite One of our oldest frenemies. Ancient latrines in Viking Denmark, the Netherlands and Lithuania contain the history of an animal we’ve lived alongside for generations, and it might hold the key to dealing with one of the developing world’s big health issues. The 55,000-year-old, rock-solid relationship exists between humans and the helminth – aka the intestinal parasite Trichuris trichiura or ‘whipworm’. Okay, so maybe it’s not so much rock-solid as pretty rocky – the whipworm causes trichuriasis, which today is a neglected tropical disease with an estimated billion human infections around the world. But this relationship has endured for a very long time – eggs from the parasite have been found in 9,000-year-old fossilised human faeces. To dive into the parasite, researchers mapped the genome of both the ancient and modern version of the whipworm to see how it’s evolved. The research has been published in Nature Communications. This is where the Viking latrines come in. Due to the eggs’ extreme durability, their internal DNA is kept well preserved if the eggs have been buried in moist soil. Fossilised poo, from the latrines of Viking settlements in Viborg and Copenhagen, provided the eggs which were then (after being sieved from the stool) subject to genetic analysis. We have known for a long time that we could detect parasite eggs up to 9000 years old under a mic“roscope. Lucky for us, the eggs are designed to survive in soil for long periods of time. Under optimal conditions, even the parasite’s genetic material can be preserved extremely well,” explains one of the researchers, University of Copenhagen parasitologist Professor Christian Kapel. “And some of the oldest eggs that we extracted DNA from are 5000 years old. It has been quite surprising to fully map the genome of 1000-year-old well-preserved whipworm eggs in this new study.” “These samples represent the oldest helminth samples and likely the oldest eukaryotic pathogens from which whole-genome sequencing data has been derived to date,” the team wrote in their new paper. “Unsurprisingly, we can see that the whipworm appears to have spread from Africa to the rest of the world along with humans about 55,000 years ago, following the so-called ‘out of Africa’ hypothesis on human migration,” explains Kapel. Today, a whipworm can grow five to seven centimetres in length and live unnoticed in the intestine of a healthy individual for several months. During this time, it lays eggs continuously, which are expelled through faeces. In people with weakened immune systems, whipworm can cause a wide range of gastrointestinal diseases, malnutrition and delay childhood development. Despite the disease the parasite causes being estimated to affect 500 million people in developing countries, because it is now rare in industrialized countries, it is rarely given research funding. “Our mapping of the whipworm and its genetic development makes it easier to design more effective anti-worm drugs that can be used to prevent the spread of this parasite in the world’s poorest regions,” says Kapel. https://cosmosmagazine.com/history/dna-viking-poo-55000-year-old-relationship-intestinal-parasite/ Edited September 7, 2022 by CaaC (John) Spacing correction Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted September 8, 2022 Author Subscriber Share Posted September 8, 2022 Quote 31,000-year-old skeleton found in famous Borneo rock art caves shows earliest evidence of amputation surgery The find predates the previous earliest amputation by 24,000 years. Evidence of what is believed to be the earliest known amputation in human history has been found by a team of Australian and Indonesian archaeologists in Borneo. The 31,000-year-old skeleton missing its left foot was found in caves on the island famous for their rock art. The discovery, which predates other instances of stone age surgery across Europe and Asia by tens of thousands of years, is published in Nature. The individual died in their early twenties, six to nine years after their foot was amputated. Remarkably, the body shows that the wound fully healed with no signs of infection and indications that the individual would have occasionally hobbled on the stump that was left behind after the surgery. Lead author Dr Tim Maloney, an archaeologist from Griffith University in Queensland, said the find might change our perceptions of ancient communities. “This is a really strong case that this individual and their community had developed advanced medical understanding to be able to successfully amputate the lower left leg of a child, enabling them to not only survive the procedure, but live a quite a thriving life in this environment into their adulthood,” he said. Low mortality rates after amputation surgery is a relatively modern development as antiseptic techniques developed in the early 20th century. “There’s a very strong case we make for understanding of the needs for antiseptic and antimicrobial management.” “It rewrites our understanding of the development of this medical knowledge, all of which is otherwise known to archaeologists from more recent agricultural and settled societies,” Maloney adds. He says the find challenges the idea that complex medical procedures developed in large, settled agricultural societies. The individual’s body was found in Liang Tebo cave, a “cathedral-like” cavity famous for some of the world’s earliest rock art, in East Kalimantan in Indonesian Borneo. Though the art, which includes depictions of deer hunting, is difficult to date, the scientists are certain it is more than 10,000 years old making it among the oldest in the world. On the neighbouring Indonesian island of Sulawesi are the world’s oldest known rock art dated at around 45,000 years old. (A two-metre-long painting of a kangaroo in Western Australia’s Kimberley region has been identified as Australia’s oldest intact rock painting at 17,500 and 17,100 years old although beyond engravings, the oldest reliably-dated rock art in Australia is 28,000 years old.) Associate Professor Renaud Joannes-Boyau explains that they were able to accurately date the human remains in Borneo from a tooth. This is because teeth are the hardiest part of the body, most resistant to decomposition. While it is tricky to say for sure if the amputated individual lived alongside the rock artists, they did find a connection between the body and the early artistic communities of the region. One piece of vibrant red ochre was found placed very close to the individual’s jaw. Maloney explains that there is strong evidence to suggest that the missing left foot is the result of a primitive “operation” as opposed to some other scenario. “The skeletal signatures we’ve discovered completely lack signals otherwise indicative of animal attacks and injuries, which would otherwise present with skeletal signals of infection and crushing fractures absent from this individual,” Maloney says. “This is a clear and a strong case that the community had a thorough understanding of negotiating veins, vessels, muscles and tissues of a child’s left leg. It reveals that this individual was a valued member of their community. It’s very unlikely that they could have lived without a high degree of community care.” “There’s a reasonable case to support the existence in the understanding of controlling blood loss and shock, some kind of antiseptic and or anti-microbial management occurring in an area of the Earth’s tropics home to a huge diversity of plant life, some of which possessing those medicinal properties,” Maloney explains. The scientists also believe that the period and usefulness of different materials suggest that the cutting edge used to perform the amputation would have most likely been a sharpened stone. Researchers suggest that the unique environmental conditions in the region may have played a role in stimulating advances in medicine. Having some of the highest levels of plant biodiversity on Earth both now and 30,000 years ago, the tropical islands of Southeast Asia will have been an area prone to would infection as well as those with medicinal properties. “We use plants for medicinal purposes we always have proving it in archaeological records is difficult, but it can be done,” says co-author Dr India Ella Dilkes-Hall, an archaeologist and archaeobotanist from the University of Western Australia. The archaeologists also point out that medical practices today’s southeast Asian and Australian communities show indications that the cultural heritage of such medical treatment may have been retained over thousands of years. “Like most archaeological riddles, there’s a fascinating record from the living indigenous cultures of Australia, in particular of a range of tooth avulsion and symbolic mourning rituals associated with with complex surgical applications in living indigenous memories,” says Maloney. “Many islands of the Indonesian archipelago similarly have fascinating living and recent records, particularly botanical medicines.” Co-author and Indonesian archaeologist Adhi Oktaviana, who is also a Griffith University PhD candidate, said: “There’s a lot of potential from botanical resources in the local community. Currently in Borneo there’s the young people, maybe they are they also using it for medicine.” https://cosmosmagazine.com/history/earliest-amputation-borneo/ Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted September 17, 2022 Author Subscriber Share Posted September 17, 2022 Quote Fossilised organs from 380-million-year-old fish help scientists get to the heart of our own evolution The fossils suggest an evolutionary leap between jawless and jawed vertebrates. The world’s oldest fossilised heart has been found in an armoured fish dug up at the Gogo Formation in Western Australia’s Kimberley region. Alongside the 380-million-year-old heart were separate fossils of a stomach, intestine and liver. Researchers involved in analysing the fossils believe that these ancient, jawed fish organs can tell us about how our own bodies evolved. The research, published in the journal Science, looks at the fossilised organs of an “arthrodire” body. Arthrodires are an extinct class of armoured fish, or placoderm, that were common in the Devonian period of Earth’s geological history which lasted from around 419 million years to 359 million years ago. Positioning of the organs in the Devonian fish’s body resemble the anatomy of modern sharks. Though arthrodires spent all their time in the water, it is believed that such jawed fish were the first vertebrates (animals with an internal spine) to take steps onto land. Hence, they can inform how all modern land vertebrates from birds and lizards to humans and other mammals evolved. FULL REPORT Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted September 20, 2022 Author Subscriber Share Posted September 20, 2022 Quote Earliest evidence of opium use found in burial site in Israel Evidence of the earliest use of the narcotic opium has been found in an ancient burial site in Israel. Traces were discovered by archaeologists in pottery vessels at the complex in Yehud, about 11km (7 miles) south-east of Tel Aviv. They say the containers date back about 3,400 years, apparently having been used in local burial rituals. The site was used by inhabitants during the period when the land was known as Canaan. The vessels had been unearthed in 2012 when the site was excavated by the Israel Antiquities Authority (IAA), but the latest findings are the result of a new study by the IAA, Tel Aviv University and The Weizmann Institute of Science. It is believed the opium was grown in what is modern-day Turkey and brought to Yehud via Cyprus. The receptacles themselves were made in Cyprus, the report says. Described as Base-Ring juglets, they were part of a number of pottery vessels thought to have been given to accompany the dead into the afterlife. They are shaped like inverted closed poppy flowers, which had long ago given rise to the hypothesis that such vessels were used in rituals for the drug. The discovery at Tel Yehud marks the first time actual traces have been found in this type of jug. "It may be that during these ceremonies, conducted by family members or by a priest on their behalf, participants attempted to raise the spirits of their dead relatives in order to express a request, and would enter an ecstatic state by using opium," said Dr Ron Beeri of the IAA. "Alternatively, it is possible that the opium, which was placed next to the body, was intended to help the person's spirit rise from the grave in preparation for the meeting with their relatives in the next life." Two years ago, researchers identified as cannabis a substance found in a 2,700-year-old temple in Tel Arad in south-east Israel. They said it might have been used in religious rituals by ancient Israelites. https://www.bbc.co.uk/news/world-middle-east-62930429 Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted September 22, 2022 Author Subscriber Share Posted September 22, 2022 (edited) Quote Chinese dinosaur egg fossils suggest dinos were in decline before asteroid impact caused their extinction The study analysed 1000 fossil egg fragments from the 2 million years before the impact. Fossil eggs from China suggest that dinosaur numbers and diversity were declining even before the asteroid impact which is widely believed to have caused a mass extinction 66 million years ago. The asteroid which hit Earth at the end of the Cretaceous period saw the end of the age of the dinosaurs and is said to have killed off three-quarters of all species on Earth. Striking waters off what is now Mexico, the 10-kilometre asteroid unleashed energy equivalent to 10 billion atomic bombs. According to the impact-driven extinction theory, all the non-avian dinosaurs were wiped out either by the explosion itself, or the acid rain and “impact winter” believed to have lasted decades after it. The removal of the non-avian dinosaurs from the scene set the stage for the emergence of mammals as Earth’s dominant animal group in the subsequent Palaeogene geological period which spanned the next 43 million years. But there is ongoing debate among palaeontologists as to whether dinosaurs were at their peak, or already on the decline in the late Cretaceous. New research published in the Proceedings of the National Academy of Sciences (PNAS) journal seem to add weight to the suggestion that dinosaurs were already on the way out even before those fateful events . Researchers from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences have found evidence that dinosaur diversity in central China was waning in the couple of million years before their extinction. The researchers hope to determine whether this trend extends throughout Asia. While the jury is still out in the palaeontological community over this hypothesis, the study in China does back up other detailed research, predominantly from North America, which suggests that dinosaur populations were already in a state of decline. The researchers looked at over 1000 fossilised dinosaur egg fragments from the Shanyang Basin in central China. Fossils were uncovered from rock sequences totalling around 150 metres in thickness. Over 5,500 Rock samples were analysed using computer modelling to accurately date the fossils. Overall, the fossils spanned a nearly 2-million-year period right up to the end of the Cretaceous and allowed the palaeontologists to zoom in to 100,000-year intervals to study the relative abundance of dinosaur species in the sediments. What they found was a decline in dinosaur diversity in the region. The 1,000 dinosaur egg fossils came from only three species: Macroolithus yaotunensis, Elongatoolithus elongatus, and Stromatoolithus pinglingensis. Two of these are from a group of toothless dinosaurs known as oviraptors, while the other is from the herbivorous, duck-billed hadrosaurid group. Additional fossil bones from the area show that a tyrannosaur and sauropod (large-bodied, long-necked dinosaur) also lived there in the same time period between about 66.4 and 68.2 million years ago. A picture emerges of a worldwide decline in dinosaur diversity in the last days of the Cretaceous. Such a sustained low number of dinosaur species for their last few million years may have resulted from global climate fluctuations and massive volcanic eruptions. There are such events known in the geological record like the Deccan Traps in India. “Our results demonstrate low dinosaur biodiversity during the last 2 million years of the Cretaceous, and those data indicate a decline in dinosaur biodiversity millions of years before the Cretaceous/Paleogene boundary,” the authors write. “The end-Cretaceous catastrophic events, such as the Deccan Traps and bolide impact, probably acted on an already vulnerable ecosystem and led to nonavian dinosaur extinction.” https://cosmosmagazine.com/history/chinese-fossils-dinosaur-decline/ Edited September 22, 2022 by CaaC (John) Spacing correction Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted September 23, 2022 Author Subscriber Share Posted September 23, 2022 Quote FULL REPORT Quote Link to comment Share on other sites More sharing options...
Subscriber CaaC (John)+ Posted September 25, 2022 Author Subscriber Share Posted September 25, 2022 Quote Ancient Mayan cities are heavily contaminated with mercury Some Mayans appeared to be fond of the toxic substance. Some ancient Mayan cities have dangerously high levels of mercury pollution. A review in Frontiers in Environmental Science has shown that this mercury pollution comes from the ancient Mayans, who appeared to use a lot of the compound at certain points in their long history. “Mercury pollution in the environment is usually found in contemporary urban areas and industrial landscapes,” says lead author Dr Duncan Cook, an associate professor of geography at the Australian Catholic University. “Discovering mercury buried deep in soils and sediments in ancient Maya cities is difficult to explain, until we begin to consider the archaeology of the region which tells us that the Maya were using mercury for centuries.” The international team of researchers reviewed all the available data on mercury contamination at ten different archaeological Mayan sites. Seven of the ten sites had mercury contamination in at least one location. These sites were mostly from the Late Classic period, during the latter half of the first millennium CE. All of the sites had been abandoned by the 10th Century. Mercury found in Greenland’s glacial meltwaters Mercury levels range from 0.016 parts per million (ppm) at Actuncan, to 17.16 ppm at Tikal. “The levels of total mercury found in some ancient contexts at Maya sites today are equal to or greater than modern guidelines we have in place for safe exposure limits for mercury in soils, such as the WHO’s recommended safe limit for mercury in soils for agriculture, which is 0.05 ppm,” says Cook. “Our review shows that numerous Maya sites have total mercury levels that, if found in a playground or a building site, would be cause for concern.” He adds that it’s “very difficult to say” how dangerous any given Maya site is, however. “We simply do not know enough yet about the mercury that is being detected at ancient Maya sites, how it got there, and what forms it takes today in the environment, 1000 or more years after the Maya.” Mayan city collapse linked to drought and social instability The researchers suggest several reasons for the mercury contamination. Vessels of pure liquid mercury have been found at several Mayan sites. At other sites, the bright red mineral cinnabar, which is made from mercury and sulphur, is a favoured pigment. “The brilliant red pigment of cinnabar was an invaluable and sacred substance, but unbeknownst to them it was also deadly and its legacy persists in soils and sediments around ancient Maya sites,” says co-author Dr Nicholas Dunning, a professor at the University of Cincinnati, US. It’s not obvious what effect this level of mercury had on the Mayan civilisation, or the health and behaviour of the residents of these cities. “What we need now is new multidisciplinary research on the Maya mercury to try and get closer to answering this question,” says Cook. “There already exists several excellent studies showing mercury present in ancient human remains from the Maya world, but we need to connect the sites with high mercury levels in buried soils and sediments to the Maya who lived there. “This means mercury analysis on human remains from the very same sites where geoscientists have detected instances of elevated mercury still present today.” Uncovering the secrets of an ancient Mayan city of Tikal Naturally occurring mercury is rare in the limestone around the Mayan region, suggesting it was imported. “We conclude that even the ancient Maya, who barely used metals, caused mercury concentrations to be greatly elevated in their environment,” says Co-author Dr Tim Beach, a professor at the University of Texas at Austin, US. Cook tells Cosmos he was one of the first researchers to identify mercury at a Maya site, back in the early 2000s – a surprising result which has “haunted him ever since”. “My colleagues and I remain fascinated by the story of how a pre-industrial society, 1000-2000 years ago, in the tropical forests of Central America, were using mercury in such a way that its chemical signature has persisted in the environment until today,” he says. https://cosmosmagazine.com/history/ancient-mayan-mercury/ Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.