Latest news with #Cretaceous
BBC News
a day ago
- General
- BBC News
Birds lived in the Arctic during the time of the dinosaurs
Experts have uncovered the earliest evidence of birds nesting in polar regions.A new study has found that they were raising their young in the Arctic seventy-three million years at the same time and in the same place dinosaurs say their findings show that birds were living in the area 30 million years earlier than previously thought. What did scientists discover? The international team was led by the University of Alaska Fairbanks in the United States and also included the University of Reading in the took took a close look at more than fifty tiny fossilised bones and teeth recovered from an Alaskan excavation were collected from the Prince Creek Formation in the US state of Alaska, an area known for its dinosaur identified a number of different types of birds - including diving birds, gull-like birds and also several kinds that are similar to modern ducks and Jacob Gardner from the University of Reading, a co-author on the study, said: "For the first time, we determined the identities of large numbers of fossils using high-resolution scans and the latest computer tools, revealing an enormous diversity of birds in this ancient Arctic ecosystem."Lauren Wilson, lead author of the study, explained the importance of their discovery."Finding bird bones from the Cretaceous [period] is already very rare. To find baby bird bones is almost unheard of. That is why these fossils are significant."Birds have existed for 150 million years. For half of the time they have existed, they have been nesting in the Arctic," she added.
Yahoo
a day ago
- General
- Yahoo
Birds have been nesting in the Arctic Circle for almost 73 million years, newly discovered fossils reveal
When you buy through links on our articles, Future and its syndication partners may earn a commission. Birds have been nesting in rugged Arctic environments for almost 73 million years, new research finds — more than 25 million years longer than was previously thought. A collection of more than 50 fossils found in northern Alaska, which include embryos and hatchlings, suggest some of the early ancestors of modern birds either migrated or adapted to the harsh polar environment in the Mesozoic era, the age of dinosaurs. "The common conception is they're too primitive to be exhibiting this advanced behavior," Lauren Wilson, lead author of the study and a doctoral student of paleontology at Princeton University, told Live Science. "So you're either dealing with [Arctic winters] as an itty-bitty, freshly hatched bird, or you're 3 months old, and having to fly about 2,000 kilometers [1,240 miles] to get to a point where it makes sense to even migrate," Wilson explained. "I don't think we would expect either of those things from these birds that don't belong to that modern lineage of birds." Whether the birds migrated south or hunkered down for the winter, the research provides the earliest known evidence of either behavior in birds. And while some modern birds, like the ivory gull (Pagophila eburnea) and snowy owl (Bubo scandiacus) are known to nest in the frigid Arctic, there is now evidence that this behavior started millions of years before the meteor that wiped out non-avian dinosaurs crashed into Earth, if not earlier. "Many birds nest in the Arctic today, and they are key parts of Arctic communities and ecosystems and food webs," Steve Brusatte, a professor of paleontology and evolution at the University of Edinburgh who peer-reviewed the study but was not involved in it, told Live Science in an email. "These fossils show that birds were already integral parts of these high latitude communities many tens of millions of years ago, and thus that these communities are a long-term norm of Earth history, not a recent ecological innovation of modern times." The fossils in the collection come from at least three different families of bird: the extinct, loon-like hesperornithes; ichthyornithes, an extinct bird that resembled seagulls; and several species resembling ducks that are within or very similar to neornithes, the group containing all modern birds. Related: Hoatzin: The strange 'stinkbird' born with clawed wings that appears to be an evolutionary 'orphan' Notably, the researchers did not find any fossils of the dominant bird group of the Cretaceous period (145 million to 66 million years ago) — enantiornithes, now-extinct birds that typically had teeth in their beaks and claws on their wings. But a few factors reveal why they likely didn't live in the Arctic. They likely took longer than other birds to incubate their eggs, they took several years to reach full adult size (where most modern birds grow to adult size within weeks) and they "may have had a period where they're almost naked because they molted their feathers simultaneously," which is not helpful during an Arctic winter, said study co-author Daniel Ksepka, a paleontologist and curator of the Bruce Museum in Connecticut. The world was warmer in the Late Cretaceous than it is today, but the region the birds were found in likely experienced freezing temperatures, snow and roughly four straight months of winter darkness. Growing to adulthood so quickly allowed modern birds to practice long-range migration and prosper during those ancient Arctic summers, which boasted around six months of 24-hour daylight and a burst in insect populations. But the weather wasn't the only challenge. They lived alongside "probably about 12 or 13 different kinds of typical dinosaurs," like the Pachyrhinosaurus, a relative of Triceratops that was about 16 feet (5 meters) long and weighed 2 tons (1,800 kilograms). Other dinosaurs like Troodon, an 11-foot tall meat-eater with short, serrated teeth, "would have happily taken advantage of a bunch of these little cute little chicks for dinner," said Patrick Druckenmiller, director of the University of Alaska Museum of the North and advising author of the study. RELATED STORIES —Chickens sprouted dino-like feathers when scientists messed with the Sonic Hedgehog gene —Why don't all birds fly? —Ancient duck-like creature discovered in Antarctica may be the oldest modern bird ever discovered To get to the fossil sites in the Prince Creek Formation in Northern Alaska, the researchers drove 500 miles (800 km) from Fairbanks, chartered a small aircraft to fly to the Colville River, then took inflatable motorboats up the river before setting up camp, Druckenmiller said. There they would look for an "orangey, pebbly, sandy" layer of sediment that contains small bones and teeth, and often lay on the permafrost to "excavate with little dental picks and small tools" from the layer itself. Now that the Prince Creek Formation is "one of the major North American Cretaceous bird sites," according to the researchers, Wilson says the next step is simply to find more fossils. "The more bones we find, the more confident we can be in exactly what types of birds we have," she said. "We might even still find a random bone that's from a bird we didn't know was there."
Hindustan Times
2 days ago
- Science
- Hindustan Times
Snakes may have once faced a vicious enemy: the humble ant
Some snakes are well-known for injecting prey with venom from their fangs. What's less well known is that they produce toxic stuff at the other end of their bodies, too. Located at the base of the tail in venomous and nonvenomous snakes alike are glands that generate foul-smelling secretions. The point of these glands has long been a mystery, but new research suggests they could stem from a time when snakes were much less impressive and needed to protect themselves from a vicious enemy: the humble ant. Scientists have known since at least the 1960s that some tail secretions are bug-repellent. One snake, a teeny, worm-like thing called the Texas blindsnake, which when coiled is no larger than a 50-pence piece, smears itself in its tail poison when raiding ant and termite nests for food, for example. Yet until now it has been unclear why all snake species, even those that seemingly never interact with ants, produce this noxious concoction. To get to the bottom of the issue, Paul Weldon of the Smithsonian Conservation Biology Institute in Virginia and Robert Vander Meer of the Centre for Medical, Agricultural and Veterinary Entomology in Florida collected secretions from snakes on all family branches of the serpentine evolutionary tree. The collection included a boa constrictor, a middle American burrowing python, a ball python, a timber rattlesnake, a king cobra and a unicolour cribo (a large, nonvenomous snake known as the 'lord of the forest'). The team then set up enclosures with red fire ants that have large underground colonies and make aggressive stinging attacks on intruders. In one chamber, the team allowed the stench of the snake gunk to waft in, to see if it would put the ants off. But they entered the chamber undeterred. Drs Weldon and Vander Meer next questioned whether directly interacting with the secretions would have an effect. They presented the ants with both a droplet of ordinary water and a droplet of water tainted with 200 microlitres of snake secretion. Though the ants readily encircled and drank from the ordinary water droplets, they rarely even approached the tainted droplets. Fascinated, the researchers then tested placing tiny amounts of secretions from four different species directly on a small handful of unlucky ants. No matter which snake provided the poison, the ants almost always became paralysed and half usually died within four hours. The researchers interpret these findings, reported recently in the Science of Nature, a journal, to mean that tail secretions from snakes probably evolved for insect defence long ago. Since both ants and snakes occupied subterranean environments during the Cretaceous period when dinosaurs still roamed the Earth, Drs Weldon and Vander Meer propose that the secretion appeared in the earliest snakes, which were probably similar to the modern Texas blindsnake. It would allow them to respond to angry ants defending themselves from attack or predatory ants looking for their next meal. As for why formidable snakes like king cobras still produce these chemicals, the team believes that they could have come to serve a dual purpose. Past work in other labs shows that carnivorous mammals steer clear of meat streaked with snake-tail secretions. Since carnivorous mammals evolved millions of years after snakes, there is little chance that pressure from mammal predators encouraged the rise of the adaptation. What is more likely is that this built-in insecticide, just by happenstance, tasted so terrible to mammals that it put them off eating snakes. When you have no limbs, you might as well make both ends count. Curious about the world? To enjoy our mind-expanding science coverage, sign up to Simply Science, our weekly subscriber-only newsletter. Get 360° coverage—from daily headlines to 100 year archives.
Yahoo
2 days ago
- General
- Yahoo
Giant 85 million-year-old mystery sea monster fossil finally identified
When you buy through links on our articles, Future and its syndication partners may earn a commission. Scientists have finally solved the mystery behind the identity of a prehistoric sea monster. The marine reptile, which could grow to around 39 feet (12 meters) long and had heavy teeth for crushing prey, was previously known from several sets of fossils unearthed over the past two decades. One key fossil was a complete but badly-preserved adult skeleton from about 85 million years ago, discovered in 1988 on Vancouver Island in British Columbia, Canada. It was thought to come from a group of long-necked reptiles known as plesiosaurs. However, until now, scientists weren't sure if it belonged to a new species or a previously discovered one. "The identity of the animal that left the fossils has remained a mystery," F. Robin O'Keefe, a professor of anatomy at Marshall University in West Virginia, said in a statement. "Our new research published today finally solves this mystery." In a new study published May 22 in the Journal of Systematic Palaeontology, O'Keefe and colleagues formally classified all the fossils as Traskasaura sandrae. This species is so different from other marine reptiles that researchers assigned it to a brand new genus, Traskasaura, within a subgroup of plesiosaurs called elasmosaurs. Elasmosaurs, like other plesiosaurs, lived throughout the Cretaceous period (145 to 66 million years ago) alongside the dinosaurs and shared the oceans with other marine reptiles, including ichthyosaurs and mosasaurs. Plesiosaurs were characterized by having small heads on long necks, broad bodies and four large, paddle-like limbs. The mythical Loch Ness Monster is usually depicted as a plesiosaur. They are thought to have breathed air and probably had to surface regularly, akin to modern-day marine mammals. The first T. sandrae specimen was unearthed in 1988 in the Haslam Formation on Vancouver Island, was formally described by scientists in 2002 and dates back to between 86 and 83 million years ago. Other fossils found in the same region include a right humerus and an "excellently preserved" juvenile skeleton. Related: Half-a-billion-year-old 3-eyed sea creature dubbed 'Mosura' breathed through big gills on its butt Although the adult specimen discovered in 1988 wasn't quite different enough from other elasmosaurs, it wasn't similar enough to any known species either. "Relatively few characters are unambiguous on this skeleton," the researchers wrote in their paper. Newer fossils also had strange traits, but they weren't complete enough to confirm the possibility of a new species. The newest juvenile skeleton specimen, however, helped shed light on these ancient creatures' features, revealing that three had the same key traits. "It has a very odd mix of primitive and derived traits — the shoulder, in particular, is unlike any other plesiosaur I have ever seen," said O'Keefe. After analyzing the features of all three fossil specimens, the researchers concluded that they must all belong to a new genus of elasmosaur. RELATED STORIES —Ancient sea monsters grew their long necks super fast after Great Dying by adding more vertebrae —Enormous 240 million-year-old sea monster had its head torn off in one clean bite —Giant 'sea dragon' fossil could be largest mosasaur ever discovered in Mississippi T. sandrae is thought to have at least 50 vertebrae in its neck. This adaptation may have made the aquatic predator extremely good at downward swimming and suggests that it hunted prey by diving from above. What about their diet? The ammonite molluscs that were plentiful in the oceans during the Cretaceous period are a "good candidate — due to Traskasaura's robust teeth, ideal, possibly, for crushing ammonite shells," O'Keefe said. "When I first saw the fossils and realized they represented a new taxon, I thought it might be related to other plesiosaurs from the Antarctic," said O'Keefe. "My Chilean colleague Rodrigo Otero thought differently, and he was right; Traskasaura is a strange, convergently evolved, fascinating beast."
The Independent
3 days ago
- Science
- The Independent
Secrets of ‘polar dinosaur' forest home revealed for first time in 120 million years
Roughly 140 million to 100 million years ago, the piece of land that is modern day Australia was located much further south on Earth. In fact, 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. Despite these harsh conditions, dinosaurs thrived here, leaving behind evidence of their existence at various palaeontological sites. For decades, scientists have come to these sites to study the rocks containing the bones of these ancient creatures in order to better understand them. My new research with palynologist Barbara Wagstaff, published in Alcheringa, builds on existing knowledge by using plant fossils from bone-bearing sites in the region to explain how the forests these dinosaurs lived in evolved – and, for the first time, illustrating them in detail. One of the warmest periods on Earth The Early Cretaceous epoch – between roughly 140 million and 100 million years ago – represents one of the warmest periods in the last half a billion years of Earth's history. The sustained warmth was a result of increased volcanic activity, which released large quantities of carbon dioxide into the atmosphere. The sustained warmth resulted in no polar ice caps, high sea levels and flooded continents. The geographic distribution of land masses was also very different back then. The supercontinent Gondwana, in which most of the southern continents we know today were clumped into a single landmass, had only just started to break apart. At the time, southernmost Australia was in the polar circle. The dinosaurs that lived in this region are known as 'polar dinosaurs'. They included small ornithopods (plant-eaters with beaks and cheeks full of teeth) and therapods (carnivorous and predatory dinosaurs). Building a picture of ancient plants For decades, palaeontologists have been studying rocks from Victorian sites. To establish the age of the recovered dinosaur bones, we've needed the expertise of palynologists – palaeontologists who study microscopic fossil spores and pollen produced by plants. Palynologists identified key species that they dissolved out of rocks. They deduced the dinosaur bones ranged in age from 130 to 100 million years old. At the same time, they were carefully recording all the microscopic spores and pollen they saw in the slides to build a picture of the plants through the Early Cretaceous period. A planet-altering transition The transition from a world without flowers to one with flowers has fascinated scientists for centuries, most famously Charles Darwin who labelled them 'an abominable mystery'. More importantly, it also forever changed our planet. Shortly after their first appearance, approximately 132 million years ago, albeit in the southern portion of the supercontinent Laurasia, we see an explosive radiation of flowering plants not only in our new record from Victoria, but also globally. What fuelled the evolution and rapid global expansion of flowering plants that dominate the Australian landscape today? Our new research suggests warmer conditions helped flowering plants migrate across the globe and colonise understorey habitats shortly after evolving. Increased competition also contributed to the turnover in understorey flora, with flowering plants outcompeting lycophytes in rapidly colonising braided river channels after flooding events. The appearance of flowering plants in the landscape resulted in the extinction of numerous understorey plants (in particular ferns) with a long fossil record. As a result, by 100 million years ago, the forests of Victoria included an open conifer-dominated forest canopy. The subcanopy beneath was made up of seed ferns and ferns. Flowering plants and ferns featured in the understorey, alongside liverworts, hornworts, lycophytes and sphagnum-like mosses. Diversifying in a warming world High carbon dioxide levels in the past made the planet warmer. This is consistent with what's happening today. As a result of these warmer conditions, cool-temperate forests thrived in the polar circle. For flowering plants, the warmer conditions provided an opportunity to diversify in an increasingly warm world. However, not all plants adapted to the warming world, with many understorey floras, including ferns, becoming extinct. The fossil record provides crucial insights into how life will respond to predicted future climate conditions because these have occurred before in Earth's history. Knowing this history is crucial to our response to the current climate change challenge. Some exciting places to visit to see fossils in Australia include Eric the Red West dig site in the Otway Ranges, Inverloch's Dinosaur Dreaming dig site in Victoria, the Dinosaur Trail along the Queensland towns of Hughenden, Richmond and Winton, and sauropod footprints in Western Australia at Gantheaume Point.
