'Jurassic World' Guesses On Dinosaur Sounds, Experts Say
"Jurassic World" features dozens of dinosaurs making ferocious sounds.
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Dinosaur Feathers Found in Amber: Photos
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A stunning array of prehistoric feathers, including dinosaur protofeathers, has been discovered in Late Cretaceous amber from Canada. The 78 to 79-million-year-old amber preserved the feathers in vivid detail, including some of their diverse colors. The collection, published in this week's Science, is among the first to reveal all major evolutionary stages of feather development in non-avian dinosaurs and birds. In this slide, an isolated barb from a vaned feather is visible trapped within a tangled mass of spider's web. BLOG: 40-Million-Year-Old Sex Act Captured in Amber
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"These specimens were most likely blown into the tacky resin, or were plucked from an animal as it brushed against resin on a tree trunk," lead author Ryan McKellar told Discovery News. "The fact that we have found some specimens trapped within spider webs in the amber would suggest that wind played an important role in bringing the feathers into contact with the resin," added McKellar, a postdoctoral fellow at the University of Alberta's Department of Earth and Atmospheric Sciences. The feather filaments shown here are similar to protofeathers that have been associated with some dinosaur skeletons. NEWS: Cretaceous African Life Sealed in Amber
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McKellar and his team made the discovery after screening over 4,000 amber samples from Grassy Lake, Alberta. The amber, collected by the Leuck family, is now housed at the Royal Tyrrell Museum. The researchers ruled out that the inclusions were mammal hairs, plant or fungal remains based on their structure. Some dinosaur fossils retain skin impressions, so the scientists could match dinosaur protofeathers (hair-like projections) to some of the objects within the amber. Here, a feather is visible near a plant bug. The high number of coils in the this feather suggests it could have come from a water-diving bird.
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The translucent tree resin provides a window into feather evolution, from non-avian dinosaurs to birds. "Part of what makes this particular set of feathers interesting is that we find the very simple Stage I and II feathers alongside advanced feathers that are very similar to those of modern birds, Stages IV and V," McKellar said. The researchers aren't yet certain why feathers first evolved, but the density of the protofeathers suggests that they helped dinosaurs with regulating temperature. Dinosaurs such as Troodon or Deinonychus may have produced the feathers. The cork-screw shaped structures in this slide are the tightly coiled bases of feather barbules.
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As feathers continued to change, they developed tufts, barbs, branching features, little hooks, and more. Some of the most advanced feathers in the collection are comparable to those of modern grebes. They appear to help diving, indicating that some of the prehistoric birds were divers. McKellar suspects the marine birds might have been Hesperornithiformes, a specialized flightless diving bird from the Dinosaur Era. This is a white belly feather of a modern grebe, showing coiled bases comparable to those seen in the Cretaceous specimen.
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Some of the feathers appear transparent now, but would have been white in life. A range of colors for the feathers is evident, though, with grays, reds and various shades of brown preserved. This, and prior research, suggests that non-avian dinosaurs and prehistoric birds could be quite flashy. The pigment within this fossilized feather suggests it would have originally been medium- or dark-brown in color. NEWS: Dino's True Colors Revealed by Tail Feathers
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In an accompanying "Perspectives" article in Science, Mark Norell points out that the dinosaur Sinosauropteryx is thought to have had a reddish banded tail, while Anchiornis likely possessed a striking black body, banded wings and a reddish head comb. Norell, chair and curator of the American Museum of Natural History's Division of Paleontology, told Discovery News that the newly discovered feathers are "very exciting." Here, a feather barb within Late Cretaceous Canadian amber shows some indication of original coloration.
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Some dino aficionados have wondered if DNA could be extracted from the feathers. "Almost anything is possible," Norell said, quickly adding that most DNA-extraction studies have been conducted on much younger amber, dating to around 20-30 million years ago, and even those led to questionable results. "Maybe bits and pieces could be identified, but not the whole genome." Shown are 16 clumped feathers in Late Cretaceous amber.
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People with amber objects, such as jewelry, also probably don't have prehistoric feather inclusions, since such items are extremely rare and dealers isolate the best pieces. Nevertheless, McKellar said, "There is some hope that you could have small feather fragments that have been overlooked." An unpigmented feather and a mite in Canadian Late Cretaceous amber.
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The new "Jurassic World" movie trailer features growling, grunting and shrieking dinosaurs. These bellows may make for good entertainment at theaters, but do paleontologists actually know how dinosaurs sounded?
Some of the dinos we've grown up with are mistakes, random limbs from museum collections that have been fastened together ... wrong.
DCI
Not really.
"It is not easy to study dinosaur sounds," said Lindsey Zanno, an assistant research professor of paleontology at North Carolina State University. "Vertebrates usually vocalize with soft tissues, and soft tissues rarely preserve in the fossil record." (Human vocal cords are made of soft tissue.)
The modern descendants of the dinosaurs -- birds and crocodiles -- vocalize in vastly different ways. Birds make noise with their syrinx, a vocal organ in the trachea that has two branches. The branches can vibrate with different frequencies at the same time, allowing birds to "sing" two different notes simultaneously, according to Terry Gates, a paleontologist at the North Carolina Museum of Natural Sciences. [ Album: Discovering a Duck-Billed Dino Baby]
"At some point, that had to evolve, and we don't know if it evolved only along the line of birds, or if it evolved before birds," which means it could have evolved in dinosaurs, Gates told Live Science.
In contrast, crocodiles can make growling rumbles even though they don't have vocal cords. Their young can even make noises before they hatchfrom their eggs, research shows.
So, besides the entertaining -- but wildly speculative -- dinosaur growls and roars in Hollywood, it's unclear how dinosaurs sounded, the researchers said.
"I think we can safely say that they made noises, but we can't say what they sounded like," said Mark Norell, the chair of paleontology at the American Museum of Natural History in New York City.
Some fossils offer clues about sounds made by crested duck-billed dinosaurs, which were large herbivores that lived during the Late Cretaceous period, between 85 million and 65 million years ago. These dinosaurs had hollow crests attached to their nasal passagesthat may have made unique sounds, Zanno said.
One duck-billed dinosaur, parasaurolophus , had a long tubular crest that started at its nose, went back over its head, and then returned to the nose. "You're looking at about seven feet of tubing before the molecule of air ever actually enters the head," Gates said.
Perhaps parasaurolophus used the crest as a resonating chamber for sound, "kind of like a trombone," he said.
Gates and his colleagues plan to study parasaurolophus sounds by taking CT scans of the dinosaur's skulls. The team hopes to construct a computer model with soft tissue inside the nasal crest and the nasal cavity, "because these soft-tissue structures are absolutely essential for creating noise," Gates said.
The research team will use vocalization models to try to figure out how the crest may have created sounds.
The work, however, has some critics. It's impossible to know how dinosaurs sounded without direct evidence about how the soft tissue functioned, researchers said.
"I consider that stuff to be really speculative and out there," Norell said. "I mean, there's really no way to tell."
Gates agreed, but also said, "I think that as long as you have a strong foundational background and you are very open in your published work, then I think it's fine to pursue such lines of inquiry."
Except for the work on duck-billed dinosaurs, dinosaur noise will likely remain a mystery. And though Hollywood may not be terribly scientific, it's fine as long as people realize it's largely entertainment, the researchers said.
"If they based it just on what we know dinosaurs, it would be a pretty boring movie," Norell said. "We're learning more all of the time, but we can't reconstruct these animals and understand them in a way we understand living animals."
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