Latest news with #JuliaClarke
Time of India
28-04-2025
- Science
- Time of India
Did dinosaurs really roar? Experts share how the animals really sounded
Image credits: Canva The most common understanding that humans have of dinosaurs comes less from research and more from the cinematic world that has presented the gigantic animals as large ferocious, roaring creatures. Be it an adult or a kid, when one thinks of dinosaurs they imagine an image of a dinosaur from Jurassic Park and not one of a fossil. Since dinosaurs were mostly seen as attacking and roaring in the movie franchise, that is how most humans have presumed these ancient animals sounded. But, did you know it's not true? According to experts, dinosaurs seldom roared. According to the BBC, there is no one way the dinosaurs sounded. The animals evolved into different shapes and sizes thus communicating differently. In a study by the New Mexico Museum of Natural History and Science , palaeontologists excavated a complete skull of a Parasaurolophus and used computer technology to simulate how the creature may have sounded. 'I would describe the sound as otherworldly. It sent chills through my spine, I remember,' said Tom Williamson to BBC. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Click Here - This Might Save You From Losing Money Expertinspector Click Here Undo Image credits: Canva As per a 2016 study published in the journal Evolution, scientists stated that rather than roaring, dinosaurs more likely made cooing or humming sounds similar to that of a pigeon or an ostrich. "To make any kind of sense of what nonavian dinosaurs sounded like, we need to understand how living birds vocalize," said Julia Clarke , a professor at the University of Texas's Jackson School of Geosciences and co-author of the study, in a press release. "This makes for a very different Jurassic world. Not only were dinosaurs feathered, but they may have had bulging necks and made booming, closed-mouth sounds." The team analysed the distribution of closed-mouth vocalization among archosaurs, a group that includes birds, crocodiles and dinosaurs to find out that 52 out of 208 investigated bird species have the vocal ability to make such sounds. Whether the ancestors of modern archosaurs actually used closed-mouth vocalization is still unknown. However, the fact that it's used by both birds and crocodiles, the two surviving groups of archosaurs, suggests that the behaviour can exist in a wide range of archosaur species, said Tobias Riede, a physiology professor at Illinois's Midwestern University and first author of the study. "The Jurassic Park films have got it wrong," said Clarke to BBC. "A lot of the early reconstructions of dinosaurs have been influenced by what we associate with scary noises today from large mammalian predators like lions. In the Jurassic Park movies, they did use some crocodilian vocalisations for the large dinosaurs, but on screen, the dinosaurs have their mouths open like a lion roaring. They wouldn't have done that, especially not just before attacking or eating their prey. Predators don't do that – it would advertise to others nearby that you have got a meal, and it would warn their prey they are there." The low-pitched sounds made by the dinosaurs may have been created by pushing the air into a pouch in the oesophagus, instead of exhaling it outside their beaks. Thus, the sound gets emitted from the skin of the neck, typically while attracting mates or defending territory.
CBC
16-03-2025
- Science
- CBC
Ancient mammals had mostly dark brown coats during the dinosaur era, new study reveals
Ancient mammals that lived in the time of dinosaurs were mostly the same dark-brown colour, according to a new study providing clues about how those mammals evolved as they faced giant predators. The study, published in the journal Science, used scientific techniques that have similarly shown the colouring of various dinosaurs and ancient birds from their fossils. Advances in dinosaur knowledge have trickled into museums and popular depictions of the animals over the past years, something the new study's authors hope can now happen for ancient mammals. "Just the way the first colour map in an extinct dinosaur opened the door to a whole new area of inquiry, this paper also does that. And that's pretty exciting," said co-author Julia Clarke, a vertebrate paleontologist at the University of Texas at Austin. Using six well-preserved fossil specimens and powerful microscopy, the researchers were able to detect the shape of pigment-producing parts of cells known as melanosomes. Previous work has shown that shape corresponds to the colour of the animal's fur. Apart from building a clearer picture of those early mammals, knowing the colour is also a huge breakthrough, according to Clarke, for understanding other aspects of the animals' lives and how they evolved over the millennia. Present-day mammals, while not as colourful as birds, do have more variety than those early mammals. "We know how important colours are for animals," said co-author Lilian D'Alba, an evolutionary biologist at the Naturalis Biodiversity Center in Leiden, Netherlands. "It's a way for animals to interact with their environment. Colours can also tell us much about how these organisms interact with temperature, humidity, with other organisms. And so we we can get a lot of information from looking at colours." Why colour matters Coat colours in mammals are important for many things, according to D'Alba, like controlling their body temperature, hiding from predators using camouflage, and being a marker of aggressiveness or strength to other animals. D'Alba said that future research could look at how mammals got more colourful coats — after a major extinction event, about 66 million years ago, killed off dinosaurs, their major predators. "The mammals that survived suddenly found themselves in a place where there was plenty of space. They had new places to colonize," she said. This was in contrast to the lives of mammals during the time of dinosaurs, when they are believed to have been active mostly at night, in the darkness, and relied more heavily on senses of smell and touch rather than vision. "So a lot of new different types of lifestyles evolved. And with these lifestyles, new environments, you see … an explosion of new species in mammals." The paper suggests that these new species came with new colours, for all the expanded activities these new mammals could now do. "It's long been the assumption that Mesozoic mammaliaforms were nocturnal, hiding in the dark to avoid being devoured by the many predatory dinosaurs and other animals would have snacked on these little animals. But, this fur colouration study is the first to find general support for this across all the fossils sampled," said Hans Larsson, associate professor and curator of vertebrate palaeontology at McGill University, who was not involved with the study. Mesozoic mammaliaforms are early mammals that lived during the time of the dinosaurs. He said the findings are interesting in understanding how being nocturnal may have led to the early evolution of many other things mammals have, including our large brains, eyesight, hearing, reproductive biology and parental care. "Ecologically, it's interesting because it suggests mammaliaforms were able to take advantage of a nocturnal lifestyle for millions of years and perfect it to the point that mammals are the dominant nocturnal predators of many of today's ecosystems," Larsson said. Fossils found in China Doing research on the colours of ancient animals can be a game of waiting and luck, according to D'Alba. The paper relied on six fossil specimens found in China, which has a few areas of the perfect geology to find these kinds of fossils. That's enough to draw an inference for most mammals during that era, according to Caleb Brown, curator of dinosaur systematics and evolution at the Royal Tyrrel Museum in Drumheller, Alta. "Most dinosaurs are known from less than one skeleton, but yet we we make inferences about their taxonomy," he said. "We have to live with that, but we also have to keep working on collecting more fossils because as you get more and more fossils, your statistical power increases." At the moment, China is where these fossils, with preserved skin or hair or feathers are being found, according to D'Alba and Brown. A lot of it depends on luck. "There's a suite of deposits in China that preserve basically lake deposits or volcanic ash deposits, and these are very fine grained sediments and very rapid burial," Brown said. "And in those cases it's quite common to find dinosaurs with feathers, but also mammals with with hair." D'Alba hopes research will continue on the mammals to learn more about those colours … and see that ending up depicted in popular culture. "The last [Jurassic Park movie] was actually quite exciting for me because they showed feather, feathered dinosaurs, and some of them had the patterns that we predicted," D'Alba said. "It's always good to see that some of the accuracy of our studies is is reaching the public."
Yahoo
05-02-2025
- Science
- Yahoo
After the asteroid, the earliest bird ancestors thrived in Antarctica
With its glaciers and sub-zero temperatures, Antarctica hardly seems like a place of refuge. However, the now icy continent might have been just that for the early ancestors of today's living waterbirds–especially after an asteroid slammed into the Earth. A newly described fossil indicates that an early relative of ducks and geese called Vegavis iaai lived in Antarctica the same time that Tyrannosaurus rex was stomping around North America. The fossil is described in a study published February 5 in the journal Nature and shows that the continent was a key location in bird evolution. After a dinosaur-killing asteroid struck the Earth near the Yucatán Peninsula in present day Mexico about 66 million years ago, about 75 percent of species on Earth eventually went extinct. However, Antarctica may have been somewhat protected because of its distance from the impact site. Fossil evidence suggests that the landmass had a temperate climate with lush vegetation, so it could have been the perfect location for the earliest members of the avian group that now includes geese and ducks. The fossil in this new study was collected in 2011 during an expedition by the Antarctic Peninsula Paleontology Project. It is a nearly complete Vegavis iaai skull, one of the earliest known birds dating back to the latest part of the Cretaceous Period (roughly 69.2 to 68.4 million years ago). The authors generated a near-complete three-dimensional reconstruction of the new skull to study its anatomy. They found that Vegavis has a long, pointed beak and a brain shape that is considered unique among all of the known birds previously discovered from the Mesozoic Era–which includes the Triassic, Jurassic, and Cretaceous Periods. During the Mesozoic, non-avian dinosaurs and an eclectic collection of early birds such as Archaeopteryx flew in different parts of the Earth. Vegavis' long beak and brain shape place it in the group that includes all modern birds and represents the earliest evidence of birds' eventual widespread distribution across the planet. Vegavis was first reported 20 years ago by study co-author Julia Clarke from The University of Texas at Austin and several colleagues. Initially, it was proposed as an early member of modern birds within the waterfowl group. However, modern birds are very rare in the fossil record from before the end-Cretaceous extinction, and more recent studies have shed some doubt on where Vegavis should be on the bird evolutionary tree. 'Few birds are as likely to start as many arguments among paleontologists as Vegavis,' Christopher Torres, a study co-author and paleontologist at the University of the Pacific, said in a statement. 'This new fossil is going to help resolve a lot of those arguments. Chief among them: where is Vegavis perched in the bird tree of life?' The nearly complete skull detailed in this new study puts some of that skepticism to rest. It shows several traits including the shape of the brain and beak bones that are consistent with that of modern birds, and waterfowl specifically. One of the main differences between modern waterflow is that Vegavis' skull has traces of powerful jaw muscles that were useful for overcoming water resistance while diving to snatch fish. Additionally, the skull features and other parts of its skeleton suggest that Vegavis used its feet for underwater propulsion while pursuing fish and other prey. This feeding strategy is more like what gerbes and loons use. [ Related: All living birds share an 'iridescent' ancestor. ] The known birds discovered in other parts of the planet from the late Cretaceous Period are barely recognizable by modern bird standards. Additionally, most of the sites that preserve delicate bird fossils from the Cretaceous yield specimens that are so incomplete that scientists can only get hints at their identity. 'This fossil underscores that Antarctica has much to tell us about the earliest stages of modern bird evolution,' study co-author and Ohio University paleontologist Patrick O'Connor said in a statement. 'And those few places with any substantial fossil record of Late Cretaceous birds, like Madagascar and Argentina, reveal an aviary of bizarre, now-extinct species with teeth and long bony tails, only distantly related to modern birds. Something very different seems to have been happening in the far reaches of the Southern Hemisphere, specifically in Antarctica.'
