Smallest and oldest dinosaur sheds light on origins of the giant species

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The Independent Online

An adult dinosaur the size of a dog and a juvenile no bigger than a hare have been unearthed by scientists who believe they have found the smallest, oldest and most primitive member of its type.

An adult dinosaur the size of a dog and a juvenile no bigger than a hare have been unearthed by scientists who believe they have found the smallest, oldest and most primitive member of its type.

The palaeontologists found the two partial skeletons in a fossil bed in China. The dinosaur, which lived 130 million years ago, has been officially named Liaoceratops yanzigouensis after the horned family of dinosaurs, which includes the three-horned triceratops, and the place in China where it was found.

Triceratops is famous for its distinctive horns and fleshy neck frill. But its miniature cousin carried a more rudimentary frill and stubby horns. It weighed 7lb rather than the massive 10 tons of triceratops. Discovering such a small and early member of this dinosaur group could help to shed light on how the horned dinosaurs evolved and split into two principal types – the main line of triceratops and the parrot-beaked psittacosaurids.

Xing Xu of the Chinese Academy of Sciences in Beijing, Peter Makovicky of The Field Museum in Chicago, and their colleagues, found the dinosaur fossils near the village of Yanzigou in the province of Western Liaoning where many of the most spectacular dinosaur finds have been unearthed.

Dr Makovicky said: "Liaoceratops demonstrates that the large, spectacular species that grace many museum exhibits are descended from some very small ancestors."

Details of the find, published in the journal Nature, explain how the rudimentary frill around the neck might have originally evolved as an anchor for powerful jaw muscles. "Pitted surface texture on the rim of the frill clearly indicates that the jaw muscles passed behind the cheek and were attached to the frill," Dr Makovicky said. "Although short, the frill is thick to counteract the contraction of these large muscles."

The stubby horns of the liaoceratops are unlikely to have evolved as a defence against predators. "Liaoceratops appears unable to protect itself against most predators, which would have included carnivorous dinosaurs and crocodiles. Instead it probably relied on concealment or flight to defend itself," he said.

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