Latest news with #Miocene
Time of India
2 days ago
- Science
- Time of India
Scientists discover 34 million year old hidden river world buried under 2 km of Antarctic ice
The North and South poles remain hidden beneath the thick icy cover of snow year-round, and as a result, most parts of the poles remain largely unexplored by humankind, concealing numerous secrets underneath. Beneath the thick ice of East Antarctica lies a hidden world, untouched for over 34 million years. This frozen expanse, more than 10 million square kilometers wide, has long concealed a forgotten landscape. The way leading to the secrets of the hidden landscape A team led by Stewart Jamieson at Durham University made this discovery with help from RADARSAT, a Canadian satellite system. The technology allowed them to detect small changes in the ice surface, revealing the shape of the land buried below. What found something as extraordinary as an ancient river-carved terrain, that was about the size of Wales, locked under nearly two kilometers of ice. 'It's like uncovering a time capsule,' Jamieson said as reported by the Brighter Side news. The untouched condition of the landscape might be due to its extreme age. Preserved beneath the ice sheet's crushing weight, the land remained unchanged since long before glaciation began. This hidden world dates back to a period when Antarctica was not the icy desert we know today. Back then, the continent was part of Gondwana, a supercontinent shared with Africa, South America, and Australia. Instead of ice, Antarctica had flowing rivers, forests, and roaming dinosaurs. That changed about 20 million years ago when glaciers took over, freezing the region's history beneath a growing sheet of ice. How did Antarctica go from Gondwana to Glaciation? The East Antarctic Ice Sheet (EAIS) began forming during the Eocene-Oligocene transition around 34 million years ago, as global temperatures plummeted and CO2 levels dropped below a critical threshold. High-altitude regions such as the Gamburtsev Subglacial Mountains and Transantarctic Mountains became nuclei for the growing ice masses. Over millions of years, these glaciers expanded, eventually combining into the massive ice sheet that persists today. The EAIS has undergone significant fluctuations throughout its history. During the Miocene period, approximately 17 to 14 million years ago, the ice sheet expanded and retreated in response to climatic shifts. Evidence from marine sediments suggests periods of retreat during warmer intervals, such as the mid-Pliocene warm period and the interglacial periods of the Pleistocene. These fluctuations left persistent imprints on the subglacial area, giving it the features that are now detectable through modern geophysical surveys. Technology tells us more Using the RADARSAT satellite system, scientists observed subtle changes in the slope of the ice's surface. These tiny clues helped reveal a massive, hidden terrain carved by rivers millions of years ago, long before the ice sheet even existed. To dig deeper, scientists used radio-echo sounding (RES) and computer models to study the land below. Their discoveries showed a landscape that didn't match modern ice flow patterns, proving it had formed long before glaciation. They even used flexural modeling to test whether ancient highlands were once part of one continuous landform, later broken up by natural erosion. But why does this matter today? Understanding this ancient environment helps scientists predict how the East Antarctic Ice Sheet (EAIS) could behave in our warming world. Jamieson's team, whose study appeared in Nature Communications, talked about the importance of this work for climate science. 'Understanding how this massive sheet might respond to human-driven climate change is a pressing concern,' he said. This discovery also tells a bigger message that the Earth's past, present, and future are deeply connected. As noted in Scientific American, these buried landscapes are like time machines. By unlocking their secrets, we can better prepare for tomorrow's climate challenges, and possibly help protect the fragile ecosystems still clinging to life today.
Yahoo
15-05-2025
- Science
- Yahoo
Newly discovered frog species from 55 million years ago challenges evolutionary tree
Australian tree frogs today make up over one third of all known frog species on the continent. Among this group, iconic species such as the green tree frog (Litoria caerulea) and the green and golden bell frog (Litoria aurea), are both beloved for their vivid colours and distinctive calls. In the Early Eocene epoch, 55 million years ago, Australia's tree frogs were hopping across the Australian continent from one billabong to the next through a forested corridor that also extended back across Antarctica to South America. These were the last remnants of ancient supercontinent Gondwana. In new research published today in the Journal of Vertebrate Paleontology, we identify Australia's earliest known species of tree frog – one that once hopped and croaked around an ancient lake near the town of Murgon in south-eastern Queensland. This research demonstrates tree frogs were present in Australia 30 million years earlier than previously thought, living alongside Australia's earliest known snakes, songbirds and marsupials. Tree frogs (Pelodryadidae) have expanded discs on their fingers and toes enabling them to climb trees. Despite their name, however, they are known to occupy a wide range of habitats, from fast-flowing streams to ephemeral ponds. Australia's previously earliest tree frogs were recovered from Late Oligocene (about 26 million years old) and Early Miocene (23 million years old) fossil deposits. Late Oligocene frog fossils were found at Kangaroo Well in the Northern Territory and Lake Palankarinna in South Australia. They were also recently found in many deposits from the Riversleigh World Heritage Area in Queensland. It has long been known that South American tree frogs and Australian tree frogs shared a common Gondwanan ancestor. What is unknown is when this common ancestor lived. Based on some molecular data, it has been estimated that the two groups separated from this common ancestor as recent as 32.9 million years ago. Our new study was based on frog fossils from a deposit near the town of Murgon, located on the traditional lands of the Waka Waka people of south-eastern Queensland. These fossils accumulated some 55 million years ago. This was between the time when a colossal meteorite took out the non-flying dinosaurs and the time when Australia broke free from the rest of Gondwana to become an isolated continent. As well as ancient frog fossils, the Early Eocene freshwater clay deposit also contains fossils of ancient bats, marsupials, snakes, non-marine birds and potentially the world's oldest songbirds. We used CT scans of frogs preserved in ethanol from Australian museum collections to compare the three-dimensional shape of the fossil bones with those of living species. This method is called three-dimensional geometric morphometrics. It has only been used on fossil frogs once before. Using these new methods, we can unravel the relationships of these fossils to all other groups of frogs – both living and extinct. From its diagnostic ilium (one of three paired pelvic bones), we identified a new species of Litoria from the family Pelodryadidae. We named this species Litoria tylerantiqua in honour of the late Michael Tyler, a renowned Australian herpetologist globally celebrated for his research on frogs and toads. Litoria tylerantiqua joins the only other Murgon frog discovered so far, the ground-dwelling Platyplectrum casca, as the oldest frogs known from Australia. Both species have living relatives in Australia and New Guinea. This demonstrates the remarkable resilience over time of some of Australia's most fragile creatures. Our new research provides crucial new understanding that helps to calibrate molecular clock studies. This is a method scientists use to estimate when different species split from a common ancestor based on the calculated rate of genetic change over time. Our research indicates the separation of Australian tree frogs and South American tree frogs is at minimum 55 million years ago. This pushes back the estimated molecular separation time for these groups by 22 million years. Unravelling the deep-time changes in the diversity and evolution of the ancestors of today's living animals can provide important new insights into the way these groups have responded in the past to previous challenges. These challenges include former natural cycles of climate change. The more we know about the fossil record, the more likely we will better anticipate future responses to similar challenges, including human-induced climate change. This is especially important for critically endangered species such as the Southern Corroboree Frog and Baw Baw Frog. Now restricted to alpine habitats in New South Wales and Victoria, they are at serious risk of extinction due to global warming. This article is republished from The Conversation. It was written by: Roy M. Farman, UNSW Sydney and Mike Archer, UNSW Sydney Read more: Two lizard-like creatures crossed tracks 355 million years ago. Today, their footprints yield a major discovery Improving human beings to make them perform better: Why is transhumanism so harmful? Antarctica has a huge, completely hidden mountain range. New data reveals its birth over 500 million years ago Roy M. Farman received funding from the Research Training Program through the University of New South Wales. Mike Archer has received funding from the Australian Research Council, the Australian Geographic Society, the National Geographic Society, the Riversleigh Society Inc and private funding from Phil Creaser (the CREATE Fund in UNSW), K. and M. Pettit, D. and A. Jeanes and other benefactors.
Miami Herald
05-05-2025
- Science
- Miami Herald
‘Strange' fossilized teeth found in Caribbean. It's a ‘giant' prehistoric species
A mystery has been building in the Caribbean. Decades ago, fossilized teeth were discovered in Cuba dating to about 18 million years ago. They were small but tapered, sharp and serrated. They were the teeth of an apex predator. Researchers didn't believe there was such an animal in the Caribbean, until they found another tooth in Puerto Rico, this time 29 million years old, according to an April 30 news release from the Florida Museum of Natural History. Still, the teeth alone weren't enough to identify the prehistoric species. Then, along a road in the Dominican Republic in 2023, paleontologists unearthed not only another tooth, but vertebrae to match, the museum said. They had an identity. It was a crocodile-like reptile 'built like a greyhound' and sometimes reaching 20 feet long — a sebecid. Not only did the Caribbean house these 'giant' predators after all, but the animals were living there millions of years after their extinction everywhere else, the museum said. Researchers described the findings and what it might mean in a study published April 30 in the peer-reviewed journal Proceedings of the Royal Society B. The cervical vertebrae and teeth were found in an embankment along the Juan Pablo II highway when roadcuts revealed sediment from the late Miocene and early Pliocene epochs, according to the study. 'Outcrops don't last too long, so you go there when you can. When they're cutting the road or a few months after that, you find the fossils. If you're looking in a few years, it will be gone,' Lázaro W. Viñola López, a former graduate student at the University of Florida and lead author on the study, said in the release. 'That emotion of finding the fossil and realizing what it is, it's indescribable,' he said. Sebecids belonged to a group of prehistoric crocodilians called Notosuchia, a group that was all but wiped out 66 million years ago, according to the museum. With dinosaurs out of the way, sebecids thrived in South America as the new apex predator, able to move quickly on land and use their teeth to rip apart their prey, the museum said. Sebecids likely wouldn't have been able to swim from mainland South America to the Caribbean islands, researchers said in the study, suggesting the landmasses were once connected by some kind of land bridge millions of years ago. There could have also been a chain of smaller islands, making the swimming distance more manageable, for the sebecids to survive in the Caribbean, the museum said. This idea is called the GAARlandia hypothesis and suggests these connections were present about 34 million years ago. 'You wouldn't have been able to predict this looking at the modern ecosystem,' Jonathan Bloch, curator of vertebrate paleontology at the Florida Museum of Natural History and co-author on the study, said in the release. 'The presence of a large predator is really different than we imagined before, and it's exciting to think about what might be discovered next in the Caribbean fossil record as we explore further back in time.' The new fossils were found in Sabana Grande De Boya in central Dominican Republic, an island nation in the eastern Caribbean. The research team includes Viñola López, Bloch, Jorge Velez-Juarbe, Philippe Münch, Juan N. Almonte Milan, Pierre-Olivier Antoine, Laurent Marivaux and Osvaldo Jimenez-Vasquez.
Yahoo
05-05-2025
- Science
- Yahoo
Scientists Found 2 New Crocodile Species Hiding in Plain Sight
Scientists know of four New World crocodile species, but a new study highlights potential fifth and sixth additions to the reptilian family. The two new crocodile species are each endemic to an island off the coast of the Yucatán—the tourist hotspot Cozumel and the atoll Banco Chinchorro. Although stable, the populations are small and are immensely vulnerable to habitat destruction. Of the estimated 8.7 million animal species on Earth, only 1.2 million of them have been officially described, with around 18,000 new species being discovered every year. Many of those are new kinds of jumping spiders, worms, insects, and other wriggling arthropods—the most abundant phylum in the animal kingdom. Huge reptiles don't typically make the list. However, a team of scientists from Canada, Mexico, and Panama claims they've discovered two previously unknown crocodile species off the Yucatán coast in a new study. With the four known species of New World crocodiles—the American, Morelet's, Cuban, and Orinoco—the addition of these two crocodile species discovered on Cozumel and the atoll Banco Chinchorro brings that number up to six. The details of these new species can be found in a new article published in the journal Molecular Phylogenetics and Evolution. 'Biodiversity is disappearing faster than we can discover what we're losing,' McGill biologist Hans Larsson, the senior author of the study, said in a press statement. 'Most species of crocodiles are already endangered, and rapid shoreline development threatens nearly every population. Our research aimed to uncover the true diversity of crocodiles on these isolated islands.' One of the oldest-living species of reptile on Earth—sharing (along with birds) some of its genetic lineage with the long-extinct dinosaur—crocodiles migrated to the Americas roughly seven million years ago during the tail end of the Miocene epoch. It's likely that a descendent of New World crocodiles, Crocodylus checchiai, traversed the Atlantic aided in part by westward ocean currents. Although well-known for its perplexingly slow rate of evolution, the crocodile eventually diversified into the four—now six—species we know today in the Americas. The discovery of these new crocs was completely unexpected, according to the study's lead author José Avila-Cervantes. Avila-Cervantes and his team compared the genetic sequences of the crocodile populations found on Cozumel and Banco Chinchorro to other known populations of New World crocodiles, and found enough genetic differentiation to necessitate a new species distinction—not just a variant of the American crocodile, the most widespread of the New World crocodiles. Scientific names have yet to be assigned to these new species, though a hat-tip to their respective island habitats seems like a good bet. Although it's always thrilling to discover a new species—especially one as large as these crocs—the study also adds a dash of concern. Although both populations are stable, they're small, in both ecosystem size and breeding population. The study estimates that each species contain fewer than 1,000 breeding individuals. 'Now that we recognize these crocodiles as distinct species, it's crucial to protect their habitats,' Larsson said in a press statement. 'Limiting land development and implementing careful conservation strategies on Cozumel and Banco Chinchorro will be key to ensuring their survival.' That could prove difficult, as both islands are popular tourist destinations. Cozumel has already seen more than 1.5 million cruise ship tourists in the first three months of 2025, which puts a strain not only on endemic species like crocodiles, but on natural wonders like the island's coral reef system. If the Cozumel and Banco Chinchorro crocodiles have any hope of survival, it'll be because the people of those islands recognize their undeniable worth to the surrounding ecosystem—the natural resource that brings millions flocking to these islands in the first place. You Might Also Like Can Apple Cider Vinegar Lead to Weight Loss? Bobbi Brown Shares Her Top Face-Transforming Makeup Tips for Women Over 50
Yahoo
01-05-2025
- Science
- Yahoo
Scientists Found Two New Crocodile Species. They Were Hiding in Plain Sight.
Scientists know of four New World crocodile species, but a new study highlights potential fifth and sixth additions to the reptilian family. The two new crocodile species are each endemic to an island off the coast of the Yucatán—the tourist hotspot Cozumel and the atoll Banco Chinchorro. Although stable, the populations are small and are immensely vulnerable to habitat destruction. Of the estimated 8.7 million animal species on Earth, only 1.2 million of them have been officially described, with around 18,000 new species being discovered every year. Many of those are new kinds of jumping spiders, worms, insects, and other wriggling arthropods—the most abundant phylum in the animal kingdom. Huge reptiles don't typically make the list. However, a team of scientists from Canada, Mexico, and Panama claims they've discovered two previously unknown crocodile species off the Yucatán coast in a new study. With the four known species of New World crocodiles—the American, Morelet's, Cuban, and Orinoco—the addition of these two crocodile species discovered on Cozumel and the atoll Banco Chinchorro brings that number up to six. The details of these new species can be found in a new article published in the journal Molecular Phylogenetics and Evolution. 'Biodiversity is disappearing faster than we can discover what we're losing,' McGill biologist Hans Larsson, the senior author of the study, said in a press statement. 'Most species of crocodiles are already endangered, and rapid shoreline development threatens nearly every population. Our research aimed to uncover the true diversity of crocodiles on these isolated islands.' One of the oldest-living species of reptile on Earth—sharing (along with birds) some of its genetic lineage with the long-extinct dinosaur—crocodiles migrated to the Americas roughly seven million years ago during the tail end of the Miocene epoch. It's likely that a descendent of New World crocodiles, Crocodylus checchiai, traversed the Atlantic aided in part by westward ocean currents. Although well-known for its perplexingly slow rate of evolution, the crocodile eventually diversified into the four—now six—species we know today in the Americas. The discovery of these new crocs was completely unexpected, according to the study's lead author José Avila-Cervantes. Avila-Cervantes and his team compared the genetic sequences of the crocodile populations found on Cozumel and Banco Chinchorro to other known populations of New World crocodiles, and found enough genetic differentiation to necessitate a new species distinction—not just a variant of the American crocodile, the most widespread of the New World crocodiles. Scientific names have yet to be assigned to these new species, though a hat-tip to their respective island habitats seems like a good bet. Although it's always thrilling to discover a new species—especially one as large as these crocs—the study also adds a dash of concern. Although both populations are stable, they're small, in both ecosystem size and breeding population. The study estimates that each species contain fewer than 1,000 breeding individuals. 'Now that we recognize these crocodiles as distinct species, it's crucial to protect their habitats,' Larsson said in a press statement. 'Limiting land development and implementing careful conservation strategies on Cozumel and Banco Chinchorro will be key to ensuring their survival.' That could prove difficult, as both islands are popular tourist destinations. Cozumel has already seen more than 1.5 million cruise ship tourists in the first three months of 2025, which puts a strain not only on endemic species like crocodiles, but on natural wonders like the island's coral reef system. If the Cozumel and Banco Chinchorro crocodiles have any hope of survival, it'll be because the people of those islands recognize their undeniable worth to the surrounding ecosystem—the natural resource that brings millions flocking to these islands in the first place. 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?
