Latest news with #TriassicPeriod
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
23-05-2025
- Science
- Yahoo
Newly identified prehistoric creature found in Canada seen as a 'fascinating beast'
May 22 (UPI) -- A group of Canadian fossils is identified as a new genus of the elasmosaurus "sea monster" that existed tens of millions of years ago, a newly published study announced. The newly identified genus officially is named the "Traskasuara sandrae," according to the study published today in the Journal of Systematic Paleontology. Elasmosaurs were large sea creatures with extremely long necks and viper-like heads with large jaws and very sharp and long teeth for capturing, crushing and consuming prey. The Traskasaura combined several "primitive and derived traits" that differ from the elasmosaurs that existed some 85 million years ago. Both are types of plesiosaurs, which were marine reptiles that existed during the late Triassic Period from about 215 million years ago to the Late Cretaceous Period about 66 million years ago. Unknown type of plesiosaur "Plesiosaur fossils have been known for decades in British Columbia," lead author F. Robin O'Keefe said. "However, the identity of the animal that left the fossils has remained a mystery, even as it was declared [British Columbia's] provincial fossil in 2023." O'Keefe said the research study published today solves the mystery of the fossils' origins. "The scientific confusion concerning this taxon is understandable," O'Keefe said. "The shoulder ... is unlike any other plesiosaur I have ever seen." The Pacific Northwest "finally has a Mesozoic reptile to call its own," said O'Keefe, who is an expert on prehistoric marine animals dating back to the age of dinosaurs and an educator at Marshall University in West Virginia. Strange and fascinating beast "Fittingly, a region known for its rich marine life today was host to strange and wonderful marine reptiles in the Age of Dinosaurs," he added. "Traskasaura is a strange, convergently evolved, fascinating beast." The Traskasaura's unique combination of physical adaptations made it an especially effective hunter from above and one of the first plesiosaurs to do so. Their necks grew to nearly 40 feet in length while their bodies resembled that of a small whale with forward flippers that propelled them through water. The marine reptile's bone structure suggests it was especially adept and downward swimming to dive onto its prey from above, while its teeth were well-suited for devouring ammonites by crushing their shells, O'Keefe said. First fossil was discovered in 1988 The first Traskasaura fossil was located along the Puntledge River in Canada's Vancouver Island in 1988 and dates to the Late Cretaceous Period. Other fossils since have been discovered, and three from theHaslam Formation on Vancouver Island are discussed in the article published in the latest edition of the Journal of Systematic Paleontology. The fossils first were discussed in 2002 and in recent years rose in global prominence after officials in British Columbia made it the province's official fossil emblem. The Traskasaura fossils are on display at The Courtenay and District Museum and Paleontology Centre in Courtenay, B.C.
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."
Ammon
30-04-2025
- Science
- Ammon
Fossils show unexpected last refuge of ferocious land-living crocs
Ammon News - 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 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 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 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 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 were built differently than the usual semiaquatic 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 many other crocs, they had protective armor made of bony plates called scutes embedded in their 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 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 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." Reuters
NDTV
30-04-2025
- Science
- NDTV
Fossils Reveal Final Refuge Of Ferocious Land-Living Crocs
Washington: 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 Vinola 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, 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 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," 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." (Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
