An enigmatic dinosaur — which sported a swan-like neck, amphibious flippers and Velociraptor-esque claws — could walk like a duck and swim like a penguin during its heyday on Earth, scientists have found after examining its fossilized remains. 
 
 In fact, the remains, which were on the black market for years, painted such a wacky image of a dinosaur that paleontologists thought it was a sophisticated fake at first. [See images of the swan-necked, amphibious dinosaur] 
 
 Its discovery reveals that the bird-like dinosaur was likely semiaquatic and felt right at home in the water, the researchers said. This is surprising because the newfound species is a theropod — a group of bipedal, mostly meat-eating dinosaurs that includes Tyrannosaurus rex — and it's thought that most theropods didn't spend much time in the water, the researchers said. (The major exception being Spinosaurus. Also, T. rex could likely swim, fossilized underwater footprints show.) 
 
 The newly identified species likely swam with its flipper-like arms, and its long neck likely helped it with foraging and ambush hunting, the researchers said. 
 
 The newfound dinosaur hails from Ukhaa Tolgod, a dinosaur graveyard in southern Mongolia. Researchers named it Halszkaraptor escuilliei, or "Halszka" for short, honoring Halszka Osmólska (1930-2008), a Polish paleontologist who specialized in Mongolian dinosaurs. The species name honors François Escuillié, who returned the poached specimen to Mongolia, the researchers wrote in the study. 
 
 "Illegally exported from Mongolia, Halszka resided in private collections around the world before it was acquired in 2015 and offered to paleontologists for study and to prepare its return to Mongolia," study senior researcher Pascal Godefroit, a paleontologist at the Royal Belgian Institute of Natural Sciences in Brussels, said in a statement. 
 
 Once H. escuilliei was safely delivered to scientists, they set about analyzing it. But the bizarre dinosaur didn't fit into any of the predatory dinosaur groups known from Mongolia. Rather, it had a mix of reptilian, avian and amphibian characteristics. It even had sickle-like "killer claws" on its feet, like those of Velociraptor, the researchers noted. 
 
 "The first time I examined the specimen, I even questioned whether it was a genuine fossil," study lead researcher Andrea Cau, a paleontologist at the Geological Museum Giovanni Capellini in Bologna, Italy, said in the statement. 
 
 To ensure the specimen was real, and not a fake configured on the black market, the researchers analyzed it with synchrotron multi-resolution X-ray microtomography. This technique allowed the researchers to take multiple X-rays that were 100 billion times more powerful than X-rays used in hospitals. The scientists then assembled these X-rays to create a virtual 3D image of the dinosaur. 
 
 Much to the scientists' delight, the results showed that the specimen appeared to be a genuine animal, and not a fake specimen pieced together from different fossils, said study co-researcher Dennis Voeten, a researcher at the European Synchrotron Radiation Facility (ESRF). 
 
 The synchrotron also revealed that the dinosaur has a number of teeth in its mouth that can't be seen with the naked eye, study co-researcher Vincent Beyrand, a researcher at the ESRF, said. "We also identified a neurovascular mesh inside its snout that resembles those of modern crocodiles to a remarkable degree," Beyrand said in the statement. "These aspects suggest that Halszka was an aquatic predator." 
 
 The synchrotron also showed that Halszka walked on two legs while on land, likely with the same posture that modern ducks have. While in the water, the bird-like dinosaur likely used its "flippers" to swim, much like penguins do today, the researchers said. [In Images: Digging Up a Swimming Dinosaur Called Spinosaurus] 
 
 Despite its odd features, Halszka isn't the only bizarre dinosaur from the Gobi Desert. Several other strange Mongolian theropods appear to be closely related to it, which prompted the researchers to create Halszkaraptorinae, a new group that is a subfamily of the dromaeosaurs, a dinosaur group commonly known as raptors. 
 
 However, some scientists are still skeptical about Halszka's validity. 
 
 It could be a weird new type of dinosaur, "but because the specimen was collected by poachers and sold on the black market, I am just not 100 percent sure it hasn't been tampered with," said Steve Brusatte, a paleontologist at the University of Edinburgh. "Some fakes these days are so sophisticated." 
 
 The conclusion that the dinosaur was semiaquatic is not a "slam dunk," Brusatte added. "The evidence is mostly circumstantial at this point," he told Live Science in an email. "For instance, the long neck is seen in many other small theropods, and is even seen in modern dinosaurs that are not aquatic, like ostriches." 
 
 Despite this uncertainty, "I'm very excited about this fossil, but I think it raises more questions than it answers, and we'll probably be debating about it for years," Brusatte said. 
 
 The study was published online yesterday (Dec. 6) in the journal Nature. 
 
 Original article on Live Science. ||||| More than 70 million years ago, a creature roaming Earth’s ancient wetlands may have looked like a duck and hunted like a duck—but it was really a dinosaur related to Velociraptor. 
 
 Described based on a nearly complete skeleton still embedded in rock, Halszkaraptor escuilliei is an unusually amphibious theropod that lived in what is now Mongolia during the late Cretaceous. At the time, the area broadly resembled today’s Egyptian Nile, with nourishing lakes and rivers that coursed through an arid, sandy landscape. 
 
 Like modern aquatic predators, this dinosaur’s face seems to have had an exquisite sense of touch, useful for finding prey in murky waters. Its small teeth would have helped it nab tiny fish, and its limber backbone and flipper-like forelimbs suggest that it cut through the water with ease. 
 
 Few other known dinosaurs display Halszkaraptor’s apparent zeal for semi-aquatic living. The giant fish-eating theropod Spinosaurus became the first dinosaur known to swim in 2014, and it may have spent most of its time in water. By contrast, Halszkaraptor’s strong hindlimbs suggest that it had no problem walking on land for extended periods. 
 
 “When I saw the fossil the first time, I was shocked,” says Andrea Cau, a paleontologist at the University of Bologna and coauthor of the study describing the dinosaur appearing this week in Nature. 
 
 “The fossil was so complete, beautifully preserved, and at the same time so enigmatic and bizarre, with a completely unexpected mix of strange features. It was the most exciting challenge for a paleontologist!” 
 
 Priceless and Poached 
 
 The strange, turkey-size animal came into scientific hands with an equally odd backstory. After millions of years entombed in rock, the fossil was dug up by poachers sometime in the recent past, probably from the Djadokhta Formation in southern Mongolia. The poachers smuggled it out of the country, likely sending it through China to the fossil markets of Europe. 
 
 Mongolia is the source of more than 5 percent of all known dinosaur species, and the country has long outlawed fossil exports. But that law has been tough to enforce, in part due to Mongolia’s size and its remote dig sites. For decades, poachers have fueled a top-dollar collector’s market, often ruining finds for paleontologists. 
 
 “We were seeing specimens basically destroyed by people who had no sympathy for the scientific value of these specimens, let alone the display value or attracting tourism,” says study coauthor Philip Currie, a paleontologist at the University of Alberta. 
 
 “Rather than collect the whole thing, they would take a pickaxe and destroy it until they found the skull and the hands and the feet.” (Find out how some scientists are trying to curb fossil poaching using special hand-held scanners.) 
 
 Some scrupulous fossil dealers, such as François Escuillié, are fighting back. Several months after returning other poached fossils to Mongolia, Escuillié learned that a new Mongolian fossil was on the market with a birdlike head and a long, gooselike neck. 
 
 Escuillié secured the fossil and flagged it to Pascal Godefroit, a paleontologist at the Royal Belgian Institute of Natural Sciences, who then alerted Cau. For now, the fossil resides in Belgium; once researchers have studied it, it will be returned to Mongolia. The species name honors Escuillié for his help. 
 
 Given the combination of strange traits and sketchy history, researchers at first worried that the fossil may have been forged. It’s a real risk: In 1999, National Geographic magazine unveiled the fossil of a birdlike dinosaur called Archaeoraptor, which ultimately turned out to be two unrelated fossils deceptively glued together. 
 
 Cau’s team took no chances. They sent this latest fossil to the European Synchrotron Radiation Facility in France, which produces some of the world’s best x-ray scans. (The facility’s scans of a fossil primate skull were so precise, researchers could see its intricate inner ear.) 
 
 The Grand Canals 
 
 After carefully analyzing some six terabytes’ worth of data, the researchers confirmed that the fossil was authentic—and utterly bizarre. 
 
 For one, the dinosaur’s snout has channels that would have ferried nerves and blood vessels to pressure sensors studding its face. In living crocodiles and aquatic birds, similar sensors provide a heightened sense of touch, helping them detect prey as it wriggles in the water. 
 
 “Even if you break the specimen, you would not be able to recognize these structures,” says coauthor Paul Tafforeau of the synchrotron facility. “This one was really a surprise.” 
 
 In addition, the animal’s long, flexible neck may have helped it strike unsuspecting prey much like today’s herons. Its outermost fingers are unusually long—an adaptation seen in animals with flippers or webbed feet—and its hips suggest that it could kick powerfully through water. 
 
 View Images Reconstruction of the amphibious bird-like dinosaur Halszkaraptor. The fossil is named for Polish paleontologist Halszka Osmólska, who discovered one of the dinosaur's closest known relatives. Courtesy Lukas Panzarin 
 
 “This dinosaur looks like it was well-equipped to both sense and capture prey in the water, probably both on the surface and in the water column,” says Duncan Leitch, a biologist at the University of California, San Francisco, who has studied living crocodiles’ sense of touch. 
 
 
 
 Royal Tyrrell Museum paleontologist Don Henderson agrees, but he adds that Halszkaraptor had a powerful incentive to keep its land legs: its young. Current evidence suggests that like birds and crocodiles, dinosaurs needed to lay their eggs out of water. (A distantly related marine reptile that lived 245 million years ago may have given birth to live young.) 
 
 “No dinosaur is ever going to give up its legs, because it’d lose the ability to reproduce,” he says. 
 
 For Currie, the greatest joy of Halszkaraptor is that even after decades of study, dinosaur fossils can still surprise us. ||||| If it looked like a duck, did it swim like a duck? 
 
 Paleontologists studying an unusual fossil have identified a new dinosaur, related to the velociraptor, that had a neck like a swan, a snout like a goose and forelimbs like flippers. The creature’s hodgepodge of features — so strange that extra work was needed to verify the fossil’s authenticity — suggest that it might have lived on both land and in water, they reported in a paper published Wednesday in Nature. 
 
 If so, that would make the species, known as Halszkaraptor escuilliei, only the second swimming dinosaur ever found, after the ferocious spinosaurus (though even that is debated). 
 
 The clues that suggest H. escuilliei was semiaquatic include its long neck and hooked, crocodile-like teeth, which it may have used to plunge face first at fish from the water surface. The dinosaur also had a snout filled with sensory nerves that are typically seen in crocodiles and used to detect movement and temperature changes in water. Its forelimbs were shaped less like wings and more like flippers, similar to those used by marine reptiles like the plesiosaur to swim.
– The dinosaur was the size of a turkey and had a neck like a swan, teeth like a crocodile, forelimbs similar to a penguin's flippers, and clawed feet ideal for use on land. It's such a strange assortment of features that researchers who identified the new species from a fossil used X-rays to make sure the nearly complete skeleton wasn't a jumble of unrelated bones. "It looked like an alien," Vincent Fernandez, co-author of a new Nature study, tells the New York Times. "It's like a mixture of things that could have been put together." That was a legitimate concern, as the 75-million-year-old fossil found in southern Mongolia was sold on the black market before an international team of researchers got their hands on it. They say the fossil is indeed real and identify the creature as Halszkaraptor escuilliei, a relative of the velociraptor and perhaps only the second swimming dinosaur ever found. Researchers explain H. escuilliei's snout, similar to that of a goose, had sensory nerves like those crocodiles use to detect movement in water. The dinosaur's hooked teeth and long neck also would've helped it snatch fish from the surface of lakes and rivers it navigated with flipper-like forelimbs. The long digits of its non-webbed feet may have helped it swim, too, though researchers say the dinosaur likely would've laid its eggs on land, per National Geographic. The fossil—explore a virtual 3D image at Live Science—is now in Belgium but will be returned to Mongolia. For researchers, it represents all of the surprising dinosaur discoveries still to be made. Says study co-author Philip Currie, "Even in very well-known sites, we can still find new animals and show that they have an incredible diversity of forms that we never even expected before." (This equally old fossil held another surprise.)