Latest news with #LazaroViñolaLopez
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
Time of India
30-04-2025
- Science
- Time of India
Fossil of a prehistoric land crocodile, which grew up to 20 feet in length, found in the Caribbean
Think of a giant crocodile, almost built like a greyhound. It is so tall that some species could even be 20 feet in length. That's sebecid. They ruled the South American landscape after the mass extinction that killed the dinosaurs 66 million years ago. It was believed that they all died out around 11 million years ago. However, paleontologists have now found fossil evidence that shows that these fearsome creatures also lived in the Caribbean, years after they were thought to have vanished. The findings of the new study is published in the Proceedings of the Royal Society B .The study's lead author, Lazaro Viñola Lopez, who conducted the research as a graduate student at the University of Florida, said that he knew his team members had come upon something exceptional when they unearthed the fossils. 'That emotion of finding the fossil and realizing what it is, it's indescribable,' he said in a statement. Illustration by Jorge Machuky 'The first question that we had when these teeth were found in the Dominican Republic and on other islands in the Caribbean was: What are they?' Jonathan Bloch, curator of vertebrate paleontology at the Florida Museum of Natural History, said. Previously, paleontologists had discovered sebecid -like teeth in Cuba and Puerto Rico, one set dating back 18 million years, another 29 million years. The tapered shapes and fine serrations on the teeth hinted that they belonged to top predators. However, until now, the lack of skeletal remains has made it difficult for researchers to conclude. That changed in early 2023, when a research team unearthed a fourth fossilized tooth and two vertebrae in the Dominican Republic. The fossils belonged to a sebecid and hinted that the Caribbean was a haven for these large terrestrial predators for at least 5 million years after they disappeared from other parts of the world. representational img These giant creatures were the last surviving members of the Notosuchia, a large and diverse group of extinct crocodilians with a fossil record that extends back into the age of dinosaurs. They vary in size, diet, and habitat, and were notably different from their crocodile relatives. How different? Well, most of the sebecids lived entirely on land! Similar to carnivorous dinosaurs, sebecids sprinted after prey on their four long, agile limbs and tore through flesh with their notorious teeth. Built like a greyhound, with some even reaching 20 feet in length, they had protective armor made of bony plates embedded in their skin. The mass extinction that took place 66 million years ago, which wiped out nonavian dinosaurs, nearly destroyed notosuchians as well. In South America, only the sebecids endured, and with the dinosaurs gone, they quickly rose to be the top predator. Representative img According to a hypothesis theory by the team, a pathway of temporary land bridges or a chain of islands once allowed land animals to travel from South America to the Caribbean. If, as the scientists think, the serrated teeth found on other Caribbean islands also came from sebecids, it means these giant reptiles once lived across the region for millions of years. Today, they're gone, and smaller predators like birds, snakes, and crocodiles have taken their place. 'You wouldn't have been able to predict this looking at the modern ecosystem. 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,' Bloch said. 100 Days Of Trump: Tariff Tyranny, Zelensky Bashing, Iran Nuclear Threat | 3 Shocking Speeches 'The sebecid is only the tip of the iceberg,' Viñola-Lopez concludes.
Yahoo
29-04-2025
- 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."
CNA
29-04-2025
- Science
- CNA
Fossils show unexpected last 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 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."
