A newly-discovered lineage of "platypus" dinosaurs that were close relative of the legendary Tyrannosaurus rex could be a vital piece in the evolutionary "jigsaw puzzle." The bones of the dinosaur were discovered in Chile by a 7-year-old boy.

The peculiar dinosaur preferred to graze on plants rather than feast on meat, the University of Birmingham reported. The Chilesaurus diegosuarezias was given its "platypus" name because of its strange combination of characteristics. For example, Chilesaurus had a proportionally small skull, hands with two fingers similar to what is seen in T. rex, and feet closer to that of long necked dinosaurs'.

"Chilesaurus can be considered a 'platypus' dinosaur because different parts of its body resemble those of other dinosaur groups due to mosaic convergent evolution. 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," said Martín Ezcurra, Researcher, School of Geography, Earth and Environmental Sciences, University of Birmingham.

The platypus dinosaur is believed to have nested within the theropod group, which were notorious meat-eaters that evolved into the birds we see today. Herbivore therpods have only been observed in the past as close bird-relatives, but these new fossils suggest a vegetarian diet was adopted much earlier than previously believed.

The Chilesaurus diegosuarezias was named in honor of Diego Suárez, the child who found the game-changing fossils. He found them at the Toqui Formation in Aysén, south of Chilean Patagonia in rocks believed to be 145 million years old. Diego stumbled on the dinosaur bones while scavenging for decorative stones with his sister, Macarena.

"Chilesaurus shows how much data is still completely unknown about the early diversification of major dinosaur groups. This study will force palaeontologists to take more care in the future in the identification of fragmentary or isolated dinosaur bones. It comes as false relationship evidence may arise because of cases of convergent evolution, such as that present in Chilesaurus," Ezcurra said.

Because of the dinosaur's strange features, researchers originally believed Diego had found a variety of species'. Since Diego's find a number of Chilesaurus diegosuarezias fossils have been excavated, revealing the bones to make up one unique species.

"Chilesaurus is the first complete dinosaur from the Jurassic Period found in Chile and represents one of the most complete and anatomically correct documented theropod dinosaurs from the southern hemisphere. Although plant-eating theropods have been recorded in North America and Asia, this is the first time a theropod with this characteristic has been found in a southern landmass," said study leader Fernando Novas, Bernardino Rivadavia Natural Sciences Museum, Buenos Aires, Argentina.

The findings were published in a recent edition of the journal Nature.