Dinosaurs at war with elephant-like ancestors

Dinosaurs living more than 200 million years ago had some serious competition from an ancestor of modern mammals the size of an elephant.

Fossil bones discovered in Poland belonged to a huge toothless plant-eater that stood on four legs and weighed nine tons.

Scientists have identified it as a dicynodont – a reptile with mammalian traits – that co-existed with the dinosaurs before they came to dominate the Earth.

Other known dicynodonts have ranged in size from rat-like burrowers to browsers as big as cows.

The newly identified species, named Lisowicia bojani, has overturned the idea that dinosaurs were the only really large land animals around during the Triassic period.

Despite their reptilian heritage, dicynodonts and their relatives were the ancestors of all modern mammals, including humans.

Dr Tomasz Sulej, one of the researchers from the Polish Academy of Sciences, said: “The discovery of Lisowicia changes our ideas about the latest history of dicynodonts, mammal Triassic relatives.

“It also raises far more questions about what really makes them and dinosaurs so large.”