Ugly duckosaur billed as killer

It’s the ultimate ugly duckling: a dinosaur with penguin flippers and the elegant neck of a swan, but with killer claws and a beak full of teeth.

Reconstruction of the amphibious bird-like dinosaur Halszkaraptor, and its fossil. Picture: Lukas Panzarin

It was the ultimate ugly duckling: a dinosaur with penguin-like flippers and the elegant neck of a swan, but also killer claws and a beak full of teeth.

A 75 million-year-old predator has redrawn scientists’ picture of the prehistoric world, suggesting that if it walks like a duck and swims like a duck, it’s probably a dinosaur. The creature, ironically unearthed in the Gobi Desert, is the only known carnivorous dinosaur that clearly lived an amphibious lifestyle.

Its discovery proves that theropod dinosaurs, which dominated every landmass during their 160 million-year supremacy, also conquered the water.

“It illustrates how much of the diversity of dinosauria remains undiscovered, even in intensely studied regions such as Mongolia,” the researchers report today in the journal Nature.

The team said the creature shared a “mosaic of features” with birds and reptiles. But they had never been found before in the group of animals that included ­giants like tyrannosaurus rex, sprinters like velociraptor and flyers like archaeopteryx, before giving rise to modern birds.

“Raptorial dinosaurs not only ran and flew, but also swam,” said lead author Andrea Cau, a University of Bologna researcher who has also helped identify what is thought to be Australia’s largest theropod dinosaur.

The duckosaur has been nicknamed “Halszkaraptor” after Gobi pioneer Halszka Osmolska, a late Polish palaeontologist. Its almost complete skeleton was discovered by Mongolian fossil poachers and found its way into private collections, before researchers got hold of it in 2015.

They believe the creature, which was about the size of a goose, walked on two legs when it was on land and used its flipper-like forearms to swim. It relied on its long neck and sickle-shaped claws for hunting and foraging.

The researchers used a French synchrotron to flesh out characteristics hidden inside the rocky fossil, including teeth and sections of skeleton. Dr Cau said the synchrotron’s X-rays had also revealed a “mesh” of nerves and blood vessels near the tip of its snout, a feature shared with modern crocodiles.

He said the synchrotron’s first job had been to confirm that the fossil was a single animal and not a hotchpotch of different body parts. “The first time I examined the specimen, I questioned whether it was genuine,” he said.