Dog-like mammal not only walked with dinosaurs, it ate them

It not only walked with the dinosaurs, it ate them. The beast in question was a dog-sized mammal that lived more than 130 million years ago when dinosaurs were supposed to have no serious competition as land-based predators.

It not only walked with the dinosaurs, it ate them. The beast in question was a dog-sized mammal that lived more than 130 million years ago when dinosaurs were supposed to have no serious competition as land-based predators.

Scientists have found fossilised remains of the primitive creature that lived at the same time as the dinosaurs and was big enough and powerful enough to eat their young.

A study of the remains, which were unearthed in China, has revealed that the last meal this individual enjoyed consisted of baby, parrot-beaked dinosaurs - swallowed almost whole.

Meng Jin, the curator of palaeontology at the American Museum of Natural History in New York, and Wang Yuanqing of the Chinese Academy of Sciences in Beijing, describe the remains of the mammal, called Repenomamus, in the journal Nature. Although it does not closely resemble any mammal living today, Repenomamus grew to more than 3ft long and weighed up to 30lb.

The discovery upsets the conventional view, which sees early mammals as small, shrew-like creatures that fed on insects and that they were only able to grow more formidable once the dinosaurs had become almost instinct.

"This new evidence of larger size and predatory, carnivorous behaviour in early mammals is giving us a drastically new picture of many of the animals that lived in the age of the dinosaurs," Dr Jin said.

The last meal of Repenomamus was a juvenile psittacosaurus or "parrot lizard".

Wear marks on its teeth showed that it was not an embryo, which ruled out the idea that Repenomamus had raided a nest. Some of the psittacosaur's bones were still connected, suggesting that Repenomamus had swallowed the young dinosaurs in chunks.