It may have walked like a duck and swum like a penguin, but a flipper-limbed creature discovered in what is now Mongolia was no bird. The strange new species is the first known nonavian dinosaur that could both run and swim, researchers say.
To compensate for a long swanlike neck, probably used for dipping underwater for fish, this dino’s center of mass shifted toward its hips, allowing it to stand erect, similar to short-tailed waterfowl like ducks, scientists report December 6 in Nature. Along with the flipperlike limbs, those adaptations suggest the animal, dubbed Halszkaraptor escuilliei, probably spent much of its time in the water, say vertebrate paleontologist Andrea Cau of the Geological and Palaeontological Museum in Bologna, Italy, and his colleagues.
To study H. escuilliei in 3-D, and while still partially embedded in rock, the researchers used synchrotron radiation scanning. Zapping the fossil with high-energy X-rays illuminates structures in fine detail without causing damage.
H. escuilliei lived in the Late Cretaceous around 75 million to 71 million years ago and belonged to maniraptora, a diverse line of theropods that include both nonavian dinosaurs and birds. Although many theropods, such as the tyrannosaurs, were primarily meat eaters, H. escuilliei’s jaw, nose and number of teeth suggest it preferred fish.
Fossil in the round
Researchers used synchrotron radiation scanning, which zaps a fossil with high-energy X-rays, to study the details of Halszkaraptor escuilliei while it was still partially embedded in the rock. Then, they made a digital 3-D image of the fossil.