Latest news with #EarlyCretaceous
Time of India
6 days ago
- General
- Time of India
Discover 5 massive giant crocodiles that are now extinct
Crocodiles are some of the oldest reptiles on Earth with a history stretching back millions of years. While today's crocodiles are already impressive predators, their ancient ancestors were often on a whole different level from growing to enormous sizes that dwarf the crocodiles we know now. In this journey back in time, we'll explore five of the most massive giant crocodiles that once ruled the rivers and swamps of prehistoric Earth but have since gone extinct. Prepare to meet some truly colossal creatures that showcase the incredible diversity and power of prehistoric crocodiles. Five giant crocodiles that no longer exists Sarcosuchus Sarcosuchus which is often called 'SuperCroc' was an enormous prehistoric crocodile that lived around 112 million years ago during the Early Cretaceous period. It measured up to 12 meters (39 feet) long, which makes it about twice the size of modern crocodiles. This giant reptile had a broad snout filled with sharp teeth which was ideal for catching and crushing large prey, possibly including dinosaurs. Sarcosuchus inhabited rivers and lakes in what is now Africa and South America. Its body was covered in thick and bony armor for protection. As one of the largest crocodilians ever discovered, Sarcosuchus was a dominant apex predator in its ecosystem. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like BCP CFD: Tu oportunidad de ingresos extra principales inversores Leer más Undo Source: Wikipedia Purussaurus Purussaurus was a colossal prehistoric caiman that lived around 5 to 10 million years ago during the Miocene epoch in South America. Growing up to 10–12 meters (33–39 feet) long, it was one of the largest crocodilian species ever. Purussaurus had an enormous and powerful jaw filled with sharp teeth that were capable of crushing large prey including turtles, fish and possibly other large animals. It dominated the rivers and wetlands of its time, using its size and strength to stay at the top of the food chain. Its heavily armored body provided excellent protection against rivals and predators. Source: Dinosaur wiki Dakosaurus Dakosaurus was a fierce marine crocodile that lived around 150 million years ago during the Late Jurassic period. Unlike modern crocodiles, it was adapted to life in the ocean with a streamlined body and powerful jaws filled with sharp and serrated teeth ideal for hunting large fish and marine reptiles. Measuring up to 4 to 5 meters (13 to 16 feet) long, Dakosaurus was an apex predator of its time. It had a strong, agile build that made it a fast swimmer, dominating the coastal waters of prehistoric seas with its deadly bite and speed. Source: Fossil wiki Desmatosuchus Desmatosuchus was a large armored reptile that lived about 230 million years ago during the Late Triassic period. Though not a true crocodile, it belonged to a related group called aetosaurs which were distant relatives of modern crocodilians. Measuring around 4 to 5 meters (13 to 16 feet) long, Desmatosuchus was covered in heavy bony armor and spikes along its back and sides, providing strong protection against predators. It was primarily a plant-eater, using its beak-like mouth to feed on tough vegetation. Desmatosuchus lived in what is now North America, roaming riverbanks and floodplains. Source: Wikipedia Aegisuchus Aegisuchus was a gigantic prehistoric crocodile that lived around 95 million years ago during the Late Cretaceous period in what is now North Africa. It was nicknamed as the 'Shield Crocodile' because of the distinctive bony crest on its head, Aegisuchus could grow up to 9 meters (30 feet) long. Its unique skull shape suggests it may have had powerful jaw muscles and a strong bite that helped in ambushing large prey. Although less is known about its exact lifestyle, Aegisuchus likely lived in freshwater environments like rivers and lakes, making it one of the most fascinating extinct crocodilian species. Source: Wikipedia Also read: 9 insects that reside on human body for their survival
Borneo Post
20-05-2025
- Science
- Borneo Post
Oyster fossils offer new insights into history of global warming
Judges check oysters after being shucked during John Bil Oyster Shucking Competition at the 2022 Restaurants Canada Show in Toronto, Canada, on May 11, 2022.(Photo by Zou Zheng/Xinhua) BEIJING (May 21): Oysters are a popular delicacy on the dining table, but they also serve as natural recorders of environmental changes. Akin to the rings of a tree, the growth bands on oyster shells reveal not only the creature's age but also the climatic conditions at the time they were formed. High temperatures in summer can boost their growth and result in wider and light-colored bands, while low temperatures in winter may slow down their growth and lead to thinner and darker bands. Scientists believe that reading the growth bands on oyster fossils dating back millions of years can reveal the environmental information of the Earth's past and offer new understanding of the planet's future. A study led by scientists from China, Germany, Britain and Madagascar focused on four oyster fossils from Madagascar and the Qinghai-Tibet Plateau dating back to the Early Cretaceous (about 140 million years ago), an era when dinosaurs thrived and the climate was warm and greenhouse-like. They discovered notable seasonal variations in sea surface temperatures, along with periodic melting of polar ice sheets and glaciers, indicating that during that ancient warm era, sea temperatures did not consistently rise but fluctuated instead, with cooler periods allowing polar ice to reform. These findings, published in the international journal Science Advances earlier this month, have challenged the long-standing view of 'minimal seasonality and rare glacial activity during greenhouse climates,' revealing the complexity of Earth's climate evolution, said lead researcher Ding Lin, an academician from the Institute of Tibetan Plateau Research, Chinese Academy of Sciences (CAS). A visitor holding an oyster poses for photos at an oyster gala held in Rushan City, east China's Shandong Province, Jan. 11, 2020. (Xinhua/Guo Xulei) As early as 2014, Ding's team revealed through analysis of ostracode shell fossils that the Gangdise Mountains are older than the Himalayas. To accurately identify the growth bands, the researchers used advanced instruments to observe the microstructure of the oyster fossils and analyze their chemical composition. Global climate computing models also assisted researchers in verifying the reliability of the data. They found that in the warm Early Cretaceous, winter ocean temperatures in the Southern Hemisphere's mid-latitudes were 10 to 15 degrees Celsius lower than in summer, similar to current seasonal variations in the same region, which suggests that seasonal temperature variations were still quite noticeable under the ancient greenhouse-like climate. Moreover, seasonal glacial meltwater possibly flowed into the oceans during that time, much like the summer melting of glaciers on Greenland's ice sheet today, implying that despite the overall warm climate, glaciers still existed and would melt in summer, releasing fresh water into the oceans. 'The Early Cretaceous greenhouse Earth seems like a symphony, and its warm melodies occasionally punctuated by brief glacial notes,' said the first author He Songlin, a postdoctoral researcher at the CAS institute. He predicts that before the polar ice sheet vanishes entirely, there would be an intermediate phase characterized by periodic fluctuations in ice sheet and glacier activity due to global warming. The study highlights that climate change is not a constant warming trend. Increases in greenhouse gases can result in more frequent extreme weather rather than uniformly rising temperatures. Seagulls perch on the floating ice at the Disko Bay close to Ilulissat, Greenland, an autonomous territory of Denmark, March 22, 2025. (Xinhua/Zhao Dingzhe) The study suggests that the brief glacier events 140 million years ago were likely caused by volcanic activity and shifts in Earth's orbit. 'It reminds us that natural factors, alongside human activities, could cause unexpected cooling events in today's warming world,' said co-first author Wang Tianyang, a postdoctoral researcher at the CAS institute. Unlike the common perception of global warming as a steady rise in temperatures, the researchers warn that the climate system can behave in complex and unpredictable ways. This research opens a new window into Earth's ancient climate and reveals the planet's hidden seasonal rhythms and icy echoes, said co-author Andreas Mulch, a professor at the Senckenberg Biodiversity and Climate Research Centre. – Xinhua China climate change conservation Oysters
Yahoo
15-05-2025
- Science
- Yahoo
Dinosaur age tsunami revealed from tiny chunks of Japanese amber, study finds
When you buy through links on our articles, Future and its syndication partners may earn a commission. Scientists have discovered evidence of an ancient tsunami in Japan — which is hidden in tree amber that dates to the age of the dinosaurs. The amber samples are deformed in a particular way that suggests trees and plant debris were rapidly swept out to the ocean and sank to the seafloor around 115 million years ago, the researchers said, which the team interpreted as evidence of one or more tsunamis. The scientists published their findings today (May 15) in the journal Scientific Reports. Scientists typically estimate when tsunamis happened in the past using geological evidence such as giant fossilized boulders that were swept away and deposited onto coasts, or by looking at abrupt changes in sediment deposits near coastlines. However, it can be difficult to differentiate tsunami traces in the fossil record from severe storms, which leave similar deposits. Amber, which is fossilized tree resin — a fluid produced by trees — can also be transported to the ocean when a tsunami sweeps trees and plant debris out to sea, leaving behind a record of the tsunami event. In the new study, the researchers analyzed amber-rich silica deposits from the Shimonakagawa Quarry in northern Hokkaido, Japan, which were deposited sometime between 116 million and 114 million years ago, during the Early Cretaceous period (145 million to 100 million years ago), when this region was deep seafloor. The team used fluorescence imaging — a technique that photographs the amber samples while shining ultraviolet light onto them — to observe the amber's structure. The amber samples showed a pattern similar to what geologists call "flame structures," a deformation that happens when soft sediment is deposited somewhere and changes shape before fully hardening — resulting in upward-pointing, flame-shaped tongues between the sediment layers. Amber deposits more commonly form other shapes, as tree resin dries when exposed to air. The research team interpreted the flame structures to mean the amber was suddenly swept out from the land to the ocean by one or more tsunamis, without being exposed to the air (which would have hardened it), then sank to the seafloor. The amber would have then been covered by a layer of silt and preserved for millions of years. "Identifying tsunamis is generally challenging," and it was not immediately apparent that tsunamis were behind the unusual amber samples, study co-author Aya Kubota, a paleontologist at Chuo University in Tokyo, told Live Science in an email. "By combining detailed field observations with the internal structures of amber, we were able to conclude that the most plausible cause was tsunamis." RELATED STORIES —Tsunamis up to 90 feet high smash into New Zealand every 580 years, study finds —1st mega-tsunami on record since antiquity was triggered by Tonga volcanic eruption —'Another piece of the puzzle': Antarctica's 1st-ever amber fossil sheds light on dinosaur-era rainforest that covered South Pole 90 million years ago Other evidence from the area backed up this hypothesis, including signs of a nearby landslide around the same time that may have been caused by an earthquake; large chunks of mud seemingly ripped up by the destruction of the seafloor; and large tree trunks on what was at the time the seafloor. Severe storm waves would not have affected the seafloor in this way, and if the tree trunks were stacked slowly over time they would have shown evidence of erosion, which these trunks did not — meaning all the evidence points to a huge amount of plant debris being transported quickly and suddenly to the seafloor. The researchers suggested that looking at ocean floor geological and fossil evidence — that is, beyond just coastal evidence — paints a more complete picture of previous tsunamis, and that examining amber deposits can provide information that helps differentiate tsunamis in the prehistoric record from severe storms. "Resin offers a rare, time-sensitive snapshot of depositional processes," Kubota said. Although the study of amber has typically focused on organisms like insects trapped inside samples, "the emerging concept of 'amber sedimentology' holds exciting potential to provide unique insights into sedimentological processes," Kubota added.
Yahoo
15-05-2025
- Science
- Yahoo
See the reconstructed home of 'polar dinosaurs' that thrived in the Antarctic 120 million years ago
When you buy through links on our articles, Future and its syndication partners may earn a commission. Australia is rather isolated today, but around 120 million years ago, the island straddled the polar circle and formed a giant landmass with Antarctica. At that time, dinosaurs lived on this landmass — and thanks to a new study, we now know what their habitat looked like. New illustrations show that "polar dinosaurs" roamed cool-temperate forests crisscrossed by rivers and carpeted with large ferns. These dinosaurs included small ornithopods — herbivorous dinosaurs with beaks and cheeks full of teeth — and small theropods, which were mostly carnivorous dinosaurs that walked on two legs and often had feathers, one of the study's authors wrote in The Conversation. "What is now Victoria was once within the polar circle, up to 80 degrees south of the equator and shrouded in darkness for months at a time," wrote co-author Vera Korasidis, a lecturer in environmental geoscience at the University of Melbourne and a research associate at the Smithsonian's National Museum of Natural History. "Despite these harsh conditions, dinosaurs thrived here, leaving behind evidence of their existence at various palaeontological sites." The amount of sunlight reaching the Antarctic Circle has remained the same over the eons, but the climate was much balmier during the Cretaceous period (145 million to 66 million years ago) than it is today, with temperatures averaging between 11 and 25 degrees Fahrenheit (6 to 14 degrees Celsius) warmer than current temperatures. The Early Cretaceous (140 million to 110 million years ago), in particular, stands out as one of the warmest periods in the past 500 million years of Earth's history, Korasidis wrote, ruling out the existence of polar ice caps. Related: Dinosaurs might still roam Earth if it weren't for the asteroid, study suggests Paleontologists have been studying rocks containing dinosaur fossils from the southern Australian state of Victoria for decades, but they have also been analyzing microscopic spores and pollen grains that may be from plant life that existed near the South Pole during the Early Cretaceous, Korasidis wrote. For the new study, Korasidis and her co-author Barbara Wagstaff, a pollen and spore specialist at the University of Melbourne, examined nearly 300 pollen and spore samples from 48 sites along the Victoria coast. These samples, which date to between 130 million and 110 million years ago, shed light on the evolution of forests and floodplains where dinosaurs lived, Korasidis wrote. The researchers published their findings and the first-ever reconstructions of Early Cretaceous polar landscapes Wednesday (May 7) in the journal Alcheringa. RELATED STORIES —T. rex may have evolved in North America after all, scientists say —T. rex researchers eviscerate 'misleading' dinosaur leather announcement —What was the fastest dinosaur? Ancient conifers made up most of the forest canopy, while ferns — specifically, scaly tree ferns (Cyatheaceae), forked ferns (Gleicheniaceae) and another group of primitive ferns (Schizaeaceae) — dominated the understory, according to the study. The researchers noticed an abundance of flowering plants appeared starting around 113 million years ago, which agrees with the timing of the proliferation of flowering plants globally. "The appearance of flowering plants in the landscape resulted in the extinction of numerous understorey plants," Korasidis wrote in The Conversation. "As a result, by 100 million years ago, the forests of Victoria included an open conifer-dominated forest canopy. Flowering plants and ferns featured in the understorey, alongside liverworts, hornworts, lycophytes and sphagnum-like mosses." The changing vegetation likely influenced dinosaurs, with many expanding their diet to include flowering plants by the end of the Cretaceous, according to Smithsonian magazine.
Canada Standard
13-05-2025
- Science
- Canada Standard
Oyster fossils offer new insights into history of global warming
Judges check oysters after being shucked during John Bil Oyster Shucking Competition at the 2022 Restaurants Canada Show in Toronto, Canada, on May 11, 2022.(Photo by Zou Zheng/Xinhua)BEIJING, May 13 (Xinhua) -- Oysters are a popular delicacy on the dining table, but they also serve as natural recorders of environmental to the rings of a tree, the growth bands on oyster shells reveal not only the creature's age but also the climatic conditions at the time they were formed. High temperatures in summer can boost their growth and result in wider and light-colored bands, while low temperatures in winter may slow down their growth and lead to thinner and darker believe that reading the growth bands on oyster fossils dating back millions of years can reveal the environmental information of the Earth's past and offer new understanding of the planet's future.A study led by scientists from China, Germany, Britain and Madagascar focused on four oyster fossils from Madagascar and the Qinghai-Tibet Plateau dating back to the Early Cretaceous (about 140 million years ago), an era when dinosaurs thrived and the climate was warm and discovered notable seasonal variations in sea surface temperatures, along with periodic melting of polar ice sheets and glaciers, indicating that during that ancient warm era, sea temperatures did not consistently rise but fluctuated instead, with cooler periods allowing polar ice to reform.A visitor holding an oyster poses for photos at an oyster gala held in Rushan City, east China's Shandong Province, Jan. 11, 2020. (Xinhua/Guo Xulei)These findings, published in the international journal Science Advances earlier this month, have challenged the long-standing view of "minimal seasonality and rare glacial activity during greenhouse climates," revealing the complexity of Earth's climate evolution, said lead researcher Ding Lin, an academician from the Institute of Tibetan Plateau Research, Chinese Academy of Sciences (CAS).As early as 2014, Ding's team revealed through analysis of ostracode shell fossils that the Gangdise Mountains are older than the accurately identify the growth bands, the researchers used advanced instruments to observe the microstructure of the oyster fossils and analyze their chemical composition. Global climate computing models also assisted researchers in verifying the reliability of the found that in the warm Early Cretaceous, winter ocean temperatures in the Southern Hemisphere's mid-latitudes were 10 to 15 degrees Celsius lower than in summer, similar to current seasonal variations in the same region, which suggests that seasonal temperature variations were still quite noticeable under the ancient greenhouse-like seasonal glacial meltwater possibly flowed into the oceans during that time, much like the summer melting of glaciers on Greenland's ice sheet today, implying that despite the overall warm climate, glaciers still existed and would melt in summer, releasing fresh water into the oceans."The Early Cretaceous greenhouse Earth seems like a symphony, and its warm melodies occasionally punctuated by brief glacial notes," said the first author He Songlin, a postdoctoral researcher at the CAS predicts that before the polar ice sheet vanishes entirely, there would be an intermediate phase characterized by periodic fluctuations in ice sheet and glacier activity due to global perch on the floating ice at the Disko Bay close to Ilulissat, Greenland, an autonomous territory of Denmark, March 22, 2025. (Xinhua/Zhao Dingzhe)The study highlights that climate change is not a constant warming trend. Increases in greenhouse gases can result in more frequent extreme weather rather than uniformly rising study suggests that the brief glacier events 140 million years ago were likely caused by volcanic activity and shifts in Earth's orbit."It reminds us that natural factors, alongside human activities, could cause unexpected cooling events in today's warming world," said co-first author Wang Tianyang, a postdoctoral researcher at the CAS the common perception of global warming as a steady rise in temperatures, the researchers warn that the climate system can behave in complex and unpredictable research opens a new window into Earth's ancient climate and reveals the planet's hidden seasonal rhythms and icy echoes, said co-author Andreas Mulch, a professor at the Senckenberg Biodiversity and Climate Research Centre.
