Latest news with #LaurenWilson
Yahoo
3 days 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."
The Guardian
4 days ago
- General
- The Guardian
Birds were nesting in the Arctic during age of dinosaurs, scientists discover
The Arctic might evoke images of polar bears and seals, but 73m years ago it was a dinosaur stomping ground. Now fossil hunters say these beasts shared their turf with a host of different birds. Researchers believe their discovery of more than 50 bird fossils from the Prince Creek formation in Alaska is the oldest evidence of birds nesting in polar regions, pushing back the date by more than 25m years. 'The previous oldest evidence for polar nesting is a penguin colony from the Eocene of Antarctica [that lived about 46.5m years ago],' said Lauren Wilson, first author of the work from Princeton University. More than 200 species of bird nest in the Arctic today, with the researchers saying they are crucial members of the ecosystem, helping with essential tasks such as pollination and seed dispersal. And the latest findings suggest their presence is nothing new. 'These new fossils fill a major gap in our understanding of bird evolution,' said Prof Patrick Druckenmiller, director of the University of Alaska Museum of the North and a co-author of the study published in the journal Science. While the earliest birds emerged in the Late Jurassic, about 150m years ago, the delicate nature of bird bones means such animals are rare in the fossil record. 'Prior to this work, and with the exception of a few footprints, bird fossils weren't known from Alaska,' said Druckenmiller. The discovery involved far more than mere good fortune, with the team carefully excavating bones as well as washing and sieving material from small, sandy deposits to isolate tiny fossils, many of which were less than 2mm in size. 'It was literally like panning for gold, except bird bones are our prize,' said Druckemiller. Wilson added that many of the bones were from embryos or hatchlings. At least one species of bird, she said, belonged to a now-extinct group called Ichthyornithes, and would have resembled a toothed seagull, while the researchers also found at least one member of another extinct group called Hesperornithes: foot-propelled diving birds with teeth. Many of the fossils came from toothless birds that may have resembled ducks. That, the team note, is significant because features such as a lack of teeth are a hallmark of Neornithes, the group that includes all living birds and their most recent common ancestor. It suggests the prehistoric birds nesting in the Arctic were close relatives of modern birds. Druckenmiller said that, like the Arctic today, the Prince Creek ecosystem of 73m years ago would have experienced about six months of continuous daylight in the summer, during which it would have been very green. As a result there would have been an abundance of food. However, the winter would have been chilly. 'While [winters were] not as harsh as today, year-round residents would have to endure freezing temperatures, occasional snowfall, and about four months of continuous winter darkness,' he said. Wilson said the newly discovered fossils showed the birds were breeding in the Arctic, but she said it was unclear if they spent the winter there, adding it was highly likely at least some of them were migratory. Steve Brusatte, a professor of palaeontology and evolution at the University of Edinburgh who was not involved in the work, said that while the fossils discovered by the team were 'absolutely minuscule', they told a huge story. 'These fossils show that birds were already integral parts of the 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,' he said.
