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Yomiuri Shimbun
27-05-2025
- Science
- Yomiuri Shimbun
Fossils Show Unexpected Last Refuge of Ferocious Land-living Crocs
Jorge Machuky / Handout via Reuters A terrestrial crocodile relative from a lineage called sebecids is seen in this image released on April 29. WASHINGTON (Reuters) — After the demise of the dinosaurs following an asteroid strike 66 million years ago, mammals became Earth's dominant land animals. But that does not mean they went unchallenged. In South America, for instance, nightmarish land-living crocs — cousins of today's crocodiles and alligators — became apex predators. This lineage of terrestrial crocs, called sebecids, lasted longer than previously believed, according to researchers who described fossils recently unearthed in the Dominican Republic that reveal that the islands of the Caribbean served as an unexpected last refuge for these ferocious predators. Until now, the most recent fossils of sebecids were found in Colombia and dated to about 10.5-12.5 million years ago. The Dominican Republic fossils date to about 5-7 million years ago. The largest of the sebecids reached roughly 6 meters long, though the partial remains from the Dominican Republic indicate an animal up to about 2 meters long. 'These were the type of predators that one thinks were from the dinosaur times,' said Lazaro Vinola Lopez, a graduate student in paleontology at the University of Florida and lead author of the research published last month in the journal Proceedings of the Royal Society B. Instead, Vinola Lopez said, sebecids were at the top of the food chain in South America during the age of mammals alongside terror birds, giant flightless birds up to about 3 meters tall with massive hooked beaks, and saber-toothed marsupials, counterparts to the saber-toothed cats of North America and elsewhere. Various types of crocs have inhabited Earth dating back to the Triassic Period more than 200 million years ago. Most, like the ones alive today, lived a semiaquatic lifestyle. But some conquered the marine realm and others lived exclusively on land, like the sebecids. The sebecids were built differently than the usual semiaquatic crocs. They had longer legs and a more upright stance, capable of running quickly to chase down prey. They had a narrow and deep skull — superficially resembling that of a meat-eating dinosaur and much different from modern crocs that have a wider and shallower skull. And the teeth of sebecids were tall and narrow with fine serrations running along the edges for cutting through meat, also similar to carnivorous dinosaurs. Like many other crocs, they had protective armor made of bony plates called scutes embedded in their skin. The fossils found in the Dominican Republic in 2023 were a single tooth that closely resembled those of South American sebecids and two vertebrae with characteristics that enabled the researchers to definitively conclude that these remains belonged to a sebecid. 'It is amazing to think that these fast-moving, dinosaur-like terrestrial crocs with serrated teeth specialized for cutting meat survived in the Caribbean hunting sloths, rodents and whatever else was around up until just a few million years ago,' said study coauthor Jonathan Bloch, curator of vertebrate paleontology at the Florida Museum of Natural History at the University of Florida. The researchers said that fossils of two teeth apparently from a sebecid dating to about 18 million years ago that were previously discovered in Cuba and a similar one dating to around 29 million years previously found in Puerto Rico suggest that this lineage was widespread in the islands of the West Indies. But how did land-living crocs from South America manage to get there? The researchers said their presence on the islands is another clue indicating there may have been a pathway of temporary land bridges or a chain of islands that permitted land animals to travel from South America to the Caribbean around 32-35 million years ago. 'The distance between the islands and northern South America was significantly shorter than what it is today. This likely facilitated the dispersal of sebecids from South America,' Vinola Lopez said. 'This shows how important islands can be as a biodiversity museum, preserving the last members of some groups that have gone extinct everywhere.'
Yahoo
26-05-2025
- Science
- Yahoo
Invasive hybrid termite species discovered in Florida
FORT LAUDERDALE, Fla. (WFLA) — A new study conducted by the University of Florida Institute of Food and Agricultural Sciences has confirmed the presence of hybrid termite colonies in South Florida. Published in the journal Proceedings of the Royal Society B, the study documents how two variations of the destructive and invasive species, the Formosan subterranean termites and Asian subterranean termites, are not only coexisting but are now crossbreeding. According to the findings, both termite species are prone to forming massive colonies and, once mature, the winged termites can be sent out to find a mate and establish a new nest as king and queen. Suspicions about their ability to breed began about 10 years ago when Thomas Chouvenc, associate professor of urban entomology at the UF/IFAS Fort Lauderdale Research and Education Center, said that they observed males and females from both species exhibiting interspecies courtship behaviors. 'This was unexpected, and it raised red flags about the possibility of hybrid populations forming in the field,' said Chouvenc. PHOTOS: Brush fire at Alafia River State Park In 2021, Chouvenc reported his team had begun collecting winged termites in the Fort Lauderdale area that didn't match the shape or form of either termite species, prompting them to ramp up monitoring. 'At first, I could not believe it, as I was hoping to never find it,' said Chouvenc. 'Since then, we have confirmed the presence of hybrid swarms every year since 2021, including in April 2025.' Genetic testing confirmed the new species to be samples of hybrid termites, sharing half of their genes with each of the two species. Fire Chief urges caution after woman pulled from water at Treasure Island Beach With this discovery, scientists warn that the repercussions of a new invasive termite species could extend far beyond Florida, which is a hotspot for the spread of invasive termites via private boats. 'This may be a Florida story now, but it likely won't stay just in Florida. Give it time,' Chauvenc warned. The hybridization process has likely been underway for a decade and is impossible to stop. However, scientists say that understanding the biology of this new termite species, and its weaknesses, could help improve pest management and foster better solutions as time goes on. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
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.
Express Tribune
02-05-2025
- Health
- Express Tribune
Scientists discover that cooler waters shield sea stars from deadly wasting disease
Listen to article A mysterious disease that has plagued sea stars for more than a decade may have met its match in the frigid waters of British Columbia's fjords. Researchers have discovered that sunflower sea stars, which are critically endangered due to sea star wasting disease (SSWD), are thriving in these cooler waters, providing valuable insight into how temperature may offer protection from the disease. The study, published in April in the Proceedings of the Royal Society B, found that the sunflower sea stars were healthier in the fjords compared to those in other areas. This discovery is significant because the species, once abundant along the Pacific coast from Baja, California to Alaska, has seen a 91% decline due to the deadly disease that causes grotesque body contortions and rapid death. The SSWD outbreak first emerged in 2013, and scientists have struggled to pinpoint the cause. While initial research pointed to a virus, subsequent studies have been inconclusive. Ian Hewson, a marine ecologist at Cornell University, says that microbial or environmental causes have also failed to provide answers. The sunflower sea star is a crucial predator in marine ecosystems, particularly in controlling sea urchin populations. Without them, sea urchins can decimate kelp forests, which provide habitats for many marine species. The discovery of sunflower sea stars thriving in cold waters may offer hope for restoring the species and its ecosystem role. The finding was made by marine ecologist Alyssa Gehman, who, along with her team, surveyed the fjords of British Columbia from 2018 to 2023. They found that while sea stars in the fjords showed signs of SSWD, the populations were healthier overall, with more adults surviving compared to populations on the outer islands. The fjords' cooler, deeper, and saltier water appeared to offer a refuge from the disease, suggesting that temperature could be a protective factor. The study also highlighted the importance of environmental conditions in shaping sea star health. Sea stars in the fjords were found in areas where snow melt created a layer of fresher, cooler water, in contrast to the warmer waters of the outer islands where the sea stars struggled to survive. The findings are a breakthrough in understanding SSWD and could provide a clue in determining the environmental conditions that either promote or prevent the disease. Researchers now believe that warmer-than-normal waters increase the likelihood of disease outbreaks, while cooler temperatures may slow or prevent its spread. Alyssa Gehman is continuing to investigate the interplay between temperature, microbial environments, and the progression of SSWD. "We've restarted the question from square one on what causes this disease," she said. This discovery offers new hope for sea star conservation and may lead to further research on how to protect vulnerable marine species from the devastating effects of climate change and disease.
Yahoo
02-05-2025
- Science
- Yahoo
Fossils show unexpected last refuge of ferocious land-living crocs
By Will Dunham WASHINGTON (Reuters) -After the demise of the dinosaurs following an asteroid strike 66 million years ago, mammals became Earth's dominant land animals. But that does not mean they went unchallenged. In South America, for instance, nightmarish land-living crocs - cousins of today's crocodiles and alligators - became apex predators. This lineage of terrestrial crocs, called sebecids, lasted longer than previously believed, according to researchers who described fossils recently unearthed in the Dominican Republic that reveal that the islands of the Caribbean served as an unexpected last refuge for these ferocious predators. Until now, the most recent fossils of sebecids were found in Colombia and dated to about 10.5-12.5 million years ago. The Dominican Republic fossils date to about 5-7 million years ago. The largest of the sebecids reached roughly 20 feet (6 meters) long, though the partial remains from the Dominican Republic indicate an animal up to about 7 feet (2 meters) long. "These were the type of predators that one thinks were from the dinosaur times," said Lazaro Viñola Lopez, a graduate student in paleontology at the University of Florida and lead author of the research published this week in the journal Proceedings of the Royal Society B. Instead, Viñola Lopez said, sebecids were at the top of the food chain in South America during the age of mammals alongside terror birds, giant flightless birds up to about 10 feet (3 meters) tall with massive hooked beaks, and saber-toothed marsupials, counterparts to the saber-toothed cats of North America and elsewhere. Various types of crocs have inhabited Earth dating back to the Triassic Period more than 200 million years ago. Most, like the ones alive today, lived a semiaquatic lifestyle. But some conquered the marine realm and others lived exclusively on land, like the sebecids. The sebecids were built differently than the usual semiaquatic crocs. They had longer legs and a more upright stance, capable of running quickly to chase down prey. They had a narrow and deep skull - superficially resembling that of a meat-eating dinosaur and much different from modern crocs that have a wider and shallower skull. And the teeth of sebecids were tall and narrow with fine serrations running along the edges for cutting through meat, also similar to carnivorous dinosaurs. Like many other crocs, they had protective armor made of bony plates called scutes embedded in their skin. The fossils found in the Dominican Republic in 2023 were a single tooth that closely resembled those of South American sebecids and two vertebrae with characteristics that enabled the researchers to definitively conclude that these remains belonged to a sebecid. "It is amazing to think that these fast-moving, dinosaur-like terrestrial crocs with serrated teeth specialized for cutting meat survived in the Caribbean hunting sloths, rodents and whatever else was around up until just a few million years ago," said study co-author Jonathan Bloch, curator of vertebrate paleontology at the Florida Museum of Natural History at the University of Florida. The researchers said that fossils of two teeth apparently from a sebecid dating to about 18 million years ago that were previously discovered in Cuba and a similar one dating to around 29 million years previously found in Puerto Rico suggest that this lineage was widespread in the islands of the West Indies. But how did land-living crocs from South America manage to get there? The researchers said their presence on the islands is another clue indicating there may have been a pathway of temporary land bridges or a chain of islands that permitted land animals to travel from South America to the Caribbean around 32-35 million years ago. "The distance between the islands and northern South America was significantly shorter than what it is today. This likely facilitated the dispersal of sebecids from South America," Viñola Lopez said. "This shows how important islands can be as a biodiversity museum, preserving the last members of some groups that have gone extinct everywhere."
