The oddball 'platypus' dinosaur scientists thought was a fake

Fossils of the strange dinosaur unearthed in southern Chile show that it was a therapod – the same group that includes Tyrannosaurus rex and the Velociraptor. But unlike those meat-eaters, the new dinosaur, named Chilesaurus diegosuarezi, was a vegetarian with both a beak and leaf-shaped teeth. It lived 150 million years ago, was just over three metres tall had strong arms, with two fingers on each hand and was bipedal, with a bird-like pelvis. Its lineage was previously unknown.

"Chilesaurus constitutes one of the most bizarre dinosaurs ever found," palaeontologist Fernando Novas of the Bernardino Rivadavia Natural Sciences Museum in Buenos Aires, told Reuters. He said the dinosaur was an evolutionary "jigsaw puzzle".

"The skeletal anatomy of Chilesaurus gathers characteristics of different dinosaur groups, like a floor is composed of mosaics of different shapes and colors. No other dinosaurs exhibit such a combination or mixture of features."

"Chilesaurus can be considered a 'platypus' dinosaur because different parts of its body resemble those of other dinosaur groups due to mosaic convergent evolution," study author Martín Ezcurra of the University of Birmingham said in a statement. "In this process, a region or regions of an organism resemble others of unrelated species because of a similar mode of life and evolutionary pressures. Chilesaurus provides a good example of how evolution works in deep time and it is one of the most interesting cases of convergent evolution documented in the history of life."

The research appears in the journal Nature.