T-Rex’s vegetarian cousin puzzles scientists

Chilesaurus diegosuarezi had a birdlike beak with leaf-shaped teeth

Tyrannosaurus rex, one of history’s most dreaded carnivores, had an oddlooking vegetarian cousin with a tiny head, long neck and stubby fingers, scientists said on Monday, admitting its anatomy had them puzzled.

Chilesaurus diegosuarezi had a birdlike beak with leafshaped teeth, evidence that it feasted on plants, but with hind leg features similar to theropod dinosaurs, the group into which it was slotted with notorious killers like T-Rex, Velociraptor and the horned Carnotaurus.

“Chilesaurus constitutes one of the most bizarre dinosaurs ever found,” Fernando Novas of Argentina’s Natural History Museum in Buenos Aires told AFP of a study published in the journal Nature, which he co-authored.

Specimens

“At the beginning, I was convinced that we had collected three different dinosaurs, but when the most complete skeleton was prepared, it [became] evident that all the elements pertained to a single dinosaur species.” The bizarre creature was named after the South American country where its fossilised remains were found, and the seven-year-old boy, Diego Suarez, who discovered the first bones in 2004 while exploring the Andes mountains with his geologist parents. About a dozen Chilesaurus specimens have since been dug up. Theropods like T-Rex tended to have relatively short necks, big heads and strong, muscled hind legs much bigger than their arms, vicious claws and jaws brimming with razor-sharp teeth.

But Chilesaurus cuts an altogether less threatening figure.

“The proportionally small skull of Chilesaurus, with the presence of a horn beak at the tip of the snout and ... leafshaped teeth, reveal that Chilesaurus was a strict plant eater,” Novas said by email.

“Its forearms were robust, but the hands were provided with just two blunt fingers.”

Most skeletons discovered so far were the size of a turkey, but isolated bones have revealed that Chilesaurus could grow to about three metres in length.

❝ At the beginning, I was convinced that we had collected three different dinosaurs, but when the most complete skeleton was prepared, it [became] evident that all the elements pertained to a single dinosaur species.”

Fernando Novas | Natural History Museum official