Media playback is unsupported on your device Media caption Kulindadromeus zabaikalicus' discovery in Siberia challenges our understanding of how dinosaurs evolved, as Pallab Ghosh reports (UK users only) 
 
 All dinosaurs were covered with feathers or had the potential to grow feathers, a study suggests. 
 
 The discovery of 150-million-year-old fossils in Siberia indicates that feathers were much more widespread among dinosaurs than previously thought. 
 
 The find "has completely changed our vision of dinosaurs", the lead researcher told BBC News. 
 
 The details have been published in the journal Science. 
 
 It is a big discovery. It has completely changed our vision of dinosaurs Dr Pascal Godefroit, Royal Belgian Institute of Natural Sciences 
 
 The creature, called Kulindadromeus zabaikalicus, was about 1m long, with a short snout, long hind legs, short arms, and five strong fingers. 
 
 Its teeth show clear adaptations for chewing plants. 
 
 Until now, fossilised evidence of feathery dinosaurs has come from China and from a meat eating group called theropods. 
 
 The latest discovery, in Russia, is from a completely separate group of plant-eating dinosaurs called ornithischians - which account for half of all dinosaurs. 
 
 Fluffy covering 
 
 The find takes the origin of feathers millions of years further back in time than had previously been thought, said Dr Pascal Godefroit of the Royal Belgian Institute of Natural Sciences in Brussels, Belgium, who led the research. 
 
 Image copyright Th.Hubin Image caption Belgian and Russian researchers discovered an area filled with ancient dinosaur bones in Kulinda, south eastern Siberia 
 
 "It was a big surprise," he said. 
 
 Instead of thinking of dinosaurs as dry, scary scaly creatures a lot of them actually had a fluffy, downy covering like feathers on a chick Dr Maria McNamara, Cork University 
 
 "The fact that feathers have now been discovered in two distinct groups, theropods in China and ornithischians in Russia means that the common ancestor of these species which might have existed 220 million years ago also probably had feathers." 
 
 The discovery has "completely changed our vision of dinosaurs", he added. 
 
 "Instead of thinking of dinosaurs as dry, scary scaly creatures a lot of them actually had a fluffy, downy covering like feathers on a chick," said co-researcher Dr Maria McNamara of Cork University in Ireland. 
 
 Alternative view 
 
 So do all the pictures of dinosaurs in children's books need to be redrawn to make creatures like Triceratops, Stegosaurus, Tyrannosaurus rex and the vicious Velociraptor, fluffier and cuter? 
 
 Image copyright Pascale Golinvaux/RBINS/Science Image caption The researchers believe the dark areas on this dinosaur fossil are remains of the earliest feathers 
 
 Perhaps a little bit, according to Professor Mike Benton, of Bristol University, who was also involved in the work. 
 
 "Our research doesn't mean that all dinosaurs had feathers, especially as adults," he told BBC News. 
 
 "Some will have had feathers as young animals and kept them throughout their lives. Others may have lost feathers as they grew up, and became large enough not to need them, or replaced feathers with scales or relied on bony plates in the skin for protection." 
 
 The key point is that dinosaurs were all initially feathered and warm blooded, confirmation of an idea that has prevailed for years, he said. 
 
 "Feathers were used first for insulation and signalling; they only later became adapted for flight." 
 
 But Dr Paul Barrett of the Natural History Museum in London, has doubts. 
 
 "Most feathers have a branching structure," he told BBC News. 
 
 "Instead these look like little streamers coming from a central plate. No bird has that structure in any part of its plumage and none of the developmental models that biologists use to understand the evolution of feathers includes a stage that has anything like that kind of anatomy." 
 
 Follow Pallab on Twitter ||||| View Images An artist's depiction of Caihong juji, a species of theropod dinosaur that lived 160 million years ago in what's now northeastern China. 
 
 Illustration by Velizar Simeonovski, The Field Museum 
 
 A new dinosaur discovered in China had feathers that may have glittered with the colors of the rainbow. Based on its stunningly preserved remains, scientists say the dinosaur’s head and chest seem to have been covered with iridescent feathers akin to those on modern hummingbirds. 
 
 The flashy display may have provided a social or sexual cue, like modern peacock tails. The dinosaur also has a bird-like body, including the sorts of feathers required for flight, but it has a crested head that more closely resembles that of a Velociraptor. 
 
 Dinosaurs 101 They ruled the Earth for more than 160 million years, but much about how dinosaurs lived and died remains a mystery. See what we know and don't know about the age of dinos. 
 
 
 
 
 
 Given these traits, the ancient animal has been named Caihong juji—Mandarin for “rainbow with the big crest”—the team reports today in the journal Nature Communications. 
 
 Caihong lived in forests and may have glided from tree to tree, preying on small mammals and lizards, says study co-author Xing Xu, a paleontologist at the Chinese Academy of Sciences. In life, the duck-size carnivore would’ve weighed roughly a pound. 
 
 “I was shocked by its beautifully preserved feathers, even though I had seen many feathered dinosaur fossils previously,” adds Xu. 
 
 View Images The slab containing Caihong juji. Exceptional conditions allowed the dinosaur's feathers to fossilize along with its bones. 
 
 Photograph by The Field Museum 
 
 Rainbow in the Dark 
 
 Birds—the last living dinosaurs—use feathers today for flight, but feathers also help birds woo potential mates or jockey for social status. Dinosaur fossils suggest that feathers originally evolved for display, only later taking on the traits needed for flight. (Learn more about how feathers evolved.) 
 
 Like modern and ancient birds, dinosaurs likely had color vision and took advantage of it with striking, feathery displays. In exceptional cases, scientists can reveal dinosaur feathers’ original colors by finding vestiges of pigment sacs called melanosomes within fossilized plumes. (See the full-body coloration of the feathered dinosaur Anchiornis.) 
 
 Yang Jan, a local farmer, found the Caihong fossil in northeastern China’s Hebei Province. In February 2014, the Paleontological Museum of Liaoning acquired the fossil from Jan. 
 
 When scientists led by Dongyu Hu, a paleontologist at China’s Shenyang Normal University, examined the fossil, they found that its well-preserved remnants contained traces of pigment in its feathers. The team sampled 66 sites across the fossil, comparing the melanosomes they saw with melanosomes from modern bird feathers. 
 
 On Caihong’s head, chest, and parts of its tail, the researchers saw melanosomes that were long, flat, and organized into sheets. These patterns most closely match the melanosomes in the iridescent throat feathers of hummingbirds. 
 
 In hummingbirds, similar structures split light like a prism, creating a metallic sheen that changes color with the viewing angle. The team couldn’t reconstruct the dinosaur feathers’ exact colors, but they suspect that the observed pigments gave Caihong a rainbow glimmer. 
 
 See Hummingbirds Fly, Shake, Drink in Amazing Slow Motion They move so fast that human eyes see only a hovering spot of color, a blur of wings. But when frozen in time by high-speed cameras, hummingbirds yield their secrets. 
 
 Paleontologists have seen this sparkle in dinosaurs before. In 2012, scientists found evidence that the feathered dinosaur Microraptor glinted blue in the sun like modern crows and grackles. Unlike Caihong, though, Microraptor was iridescent all over—and it is much younger: Microraptor lived a full 40 million years after Caihong. 
 
 “When we put these data on the evolutionary tree, we recognize two different ways of creating iridescent color in small raptor dinosaurs before the origin of birds,” says Julia Clarke, a paleontologist at the University of Texas at Austin who coauthored the Caihong and Microraptor studies. 
 
 More Than a Light Show 
 
 Caihong may not have used just its feathers for showing off, notes University of Edinburgh paleontologist Steve Brusatte, who reviewed the study before publication. 
 
 “Its plumage was a shiny rainbow of iridescent colors … but it didn't stop there,” he says. “It also had a funky crest of bone sticking up in front of its eyes, which was probably a display structure as well.” 
 
 View Images The skull of Caihong juji. 
 
 Photograph by The Field Museum 
 
 In addition, Xu says that Caihong’s frond-like tail has asymmetrical feathers, and their short, stiff leading edges would have borne the aerodynamic load of flight. Caihong is now the oldest known animal to have this key adaptation. The iconic bird-like dinosaur Archaeopteryx also has asymmetrical feathers, but it lived ten million years later. 
 
 With Caihong, “who knows what the functions of this large, wide tail were?” says National Geographic explorer Ryan Carney, a University of South Florida biologist who studies Archaeopteryx. “Perhaps it was held up as a dark background to provide contrast against the iridescent head during displays?” 
 
 Clarke, an expert on the origin of birds, says that researchers also can’t yet be sure how Caihong used its iridescent feathers, or whether males or females of the species had different plumage. For that, paleontologists can only hope for further study of the new fossil, and perhaps even more bones from Caihong and other feathered dinosaurs. ||||| "The 10,000 species of birds that live today -- from hummingbirds to ostriches -- are modern dinosaurs," Brusatte said. "They are dinosaurs in the same way that humans are mammals. The classic body plan of living birds -- feathers, wings, wishbones, air sacs extending into hollow bones -- did not evolve suddenly but was gradually assembled over tens of millions of years of evolution. But, when this body plan finally came together completely, it unlocked great evolutionary potential that allowed birds to evolve at a super-charged rate." "They underwent a burst of evolution early in their history, which eventually led to the 10,000 species alive today -- more than twice the number of mammals." Photos: Audubon Report Names Birds at Climate Risk 
 
 "The oldest birds, like Archaeopteryx that lived 150 million years ago in Germany, are very hard to distinguish from their closest dinosaurian relatives," Brusatte said. "Unlike living birds, they had teeth, sharp claws on their wings, and long tails." "Over the past two decades," he continued, "over 50 new species of Mesozoic birds have been discovered in northeastern China, in the same rock units as the famous 'feathered dinosaurs.' So many birds are preserved here because entire ecosystems were buried by volcanic eruptions, turning animals to stone like a dinosaur version of Pompeii." Tiny Feathered Dinosaur Found 
 
 Dromaeosaurids were "raptor dinosaurs" that include Velociraptor from "Jurassic Park" fame. These dinosaurs were pack hunters who wielded a sharp, hyper-extendable "killer claw" on their second toe. "One of the most recently discovered dromaeosaurids is Balaur, a poodle-sized terror from Romania which had not one, but two 'killer claws' on each foot." Velociraptor Inspires Fast Running Robot 
 
 "Troodontids were probably the smartest dinosaurs of all, as they had the largest brains relative to their body size of any dinosaur group," Brusatte said. "Most troodontids were small, fast-running dinosaurs that probably ate both meat and plants." Among the most recently discovered of this group are the small, feathered Anchiornis and Xiaotingia, which lived in China about 160 million years ago. "They look eerily similar to birds, so much so that some researchers think they could be primitive birds rather than troodontids with wings and feathers," Brusatte said. World's Earliest Bird Discovered 
 
 Oviraptorosaurs, were a group of small omnivores that were lightweight, lacked teeth and had tall, hollow crests on their skulls. The recently discovered Anzu -- the so-called " chicken from hell " -- came by its nickname honestly. It towered more than five feet tall, weighed more than 400 pounds, and was covered in a coat of feathers. 
 
 Alvarezsaurs were among the smallest dinosaurs of all, measuring just a few feet long and weighing less than 5 kilograms (10 pounds). "Some of them had only a single functional finger on their hand, which they probably used to prod deep into the nests of bugs, which were one of their main food sources," Brusatte said. New Dinosaur Bolsters Bird-Dino Connection 
 
 Brusatte describes therizinosaurs as "perhaps the weirdest theropods of all." "These were big, bulky, cumbersome dinosaurs that ate plants. They had fat barrel-shaped chests, stocky legs, and big claws on their arms," Brusatte said. For many years paleontologists argued about which group this dinosaur belonged to, only recently settling on theropods. This means they were fairly closely related to birds, despite their weird anatomy. Nests of Big-Clawed Dinosaurs Found in Mongolia 
 
 Ornithomimosaurs were theropods called "ostrich mimic" dinosaurs -- for a reason. "Like living ostriches, they could run fast on their long legs and used their sharp, toothless beaks to eat a varied diet of small prey, plants, and perhaps even small shrimps in the water just like living flamingos," Brusatte explained. "A recent find in Canada showed that not only were ornithomimosaurs feathered, but they also had complex feathers on their arms that would have formed something of a wing, although they couldn't fly." 
 
 "Some of the rarest theropods (two-legged carnivorous dinos) of all, compsognathids are represented by about half a dozen species," Brusatte said. "They were small, sleek meat-eaters which ate small prey like lizards." One of the more recent finds, Juravenator from Germany, is known from a nearly complete fossil. Dinosaurs That Loved the Nightlife 
 
 Paleontologists have just assembled the most comprehensive family tree of meat-eating dinosaurs. Published in the journal Current Biology, the family tree reveals how diverse carnivorous dinosaurs were and how birds eventually evolved from them. Tyrannosaurs, including Tyrannosaurus rex , are one key group on the meat-loving dino family tree. Lead author Steve Brusatte of the University of Edinburgh's School of GeoSciences told Discovery News, "The most iconic dinosaurs of all, tyrannosaurs were more than just the 13-meter-long (nearly 43 feet long), 5-ton monster predator T. rex ." "Tyrannosaurs were an ancient group that originated more than 100 million years before T. rex , and for almost all of their evolutionary history they were small carnivores not much bigger than a human in size." New T-Rex Tracks Add to Pack-Hunting Theory 
 
 Dinosaurs not only danced, but they also did so with such enthusiasm that they left behind fossilized footprints as evidence of their moves, a new paper by an international team of paleontologists reports. 
 
 Play Video Dinosaur Sex: How Did That Work? Dinosaurs ruled the planet for 130 million years, so clearly they knew how to perpetuate themselves, but scientists have not had much to go on, in terms of their exact mechanics for doing the deed. DCI 
 
 The discovery confirms prior speculation, based on dinosaur head crests and colorful feathers, that some dinosaurs engaged in mating displays that were similar to those of modern birds. The dancing dinos, according to the paper published in the journal Scientific Reports, were likely large theropods, meaning two-legged carnivorous dinosaurs. 
 
 “They were evidently very active and perhaps driven into frenzies by the excitement of the breeding season,” project leader Martin Lockley of the University of Colorado Denver, told Discovery News. 
 
 “This is typical of some bird species,” he continued. “The extensive scrape evidence suggests much high-energy activity. If small birds get excited when breeding, imagine what big theropods might have done!” 
 
 Lockley and his team found the fossilized dinosaur scrape marks in 100-million-year-old Dakota sandstone in western Colorado. Since the footprints could not be removed from the rocks without causing damage, the scientists recreated them in virtual 3-D, using a technique of layering photographs known as photogrammetry. Rubber molds and fiberglass copies of the footprints were also made and are now stored at the Denver Museum of Nature & Science. 
 
 Various interpretations of the fossilized footprints were considered, such as whether or not dinosaurs made them while digging for food or marking territory. These were all discounted for multiple reasons, with only mating dance behavior providing the best explanation for the ancient prints. In fact, the marks closely match those created by dancing birds today, such as Atlantic puffins and ostriches. 
 
 The time and location of the prints indicate that they were made by Acrocanthosaurus, a dinosaur that grew close to 38 feet in length and weighed up to 6.8 short tons. Its rhythmic stomps and scratches, comprising what the researchers call a "scrape ceremony," must have reverberated for quite a distance. The dinosaur probably vocalized as it performed the ritualistic scraping and bobbing movements, as today’s birds do.
– Dinosaurs were scaly old things, right? Not so much, apparently. A Science study of 150-million-year-old fossils uncovered in Siberia is playing a big role in flipping that perception on its head, suggesting that nearly all dinosaurs actually sprouted feathers. At least five species of feathered dinosaurs have turned up in China over the last 20 years, all belonging to the theropod group of raptors. The latest fossils, however, come from a two-legged dinosaur in the ornithischian group, which National Geographic says accounts for about half of all dinosaurs. "Probably that means the common ancestor of all dinosaurs had feathers," the study author says. The fossils have "completely changed our vision of dinosaurs," he adds, per the BBC. A paleontologist not involved with the study calls it "fantastic" and says it revealed three types of feather imprints different from those of other feathered dinosaurs as well as those of modern birds: "I don't know" why they had feathers, he says. "These animals couldn't fly, that's all we can tell you." (Read about a dinosaur that did fly—with four wings.)