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 hind limbs 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 co-author 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 fuelled 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 co-author 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 Franc¸ois 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 honours 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 analysing 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 recognise these structures,” says co-author 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.
“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: it’s 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.
“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,” he says. “I doubt that we know one percent of one percent that lived in the world.”
Lead Image: 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