A new dinosaur discovered accidentally by a seven year old in Chile is one of the most unusual found to date and, as it turns out, was once the most abundant dinosaur in southwest Patagonia.
Chilesaurus diegosuarezi was found by Diego Suarez at the Toqui Formation in Aysén, south of Chilean Patagonia. He and his sister were looking for “decorative rocks” while his parents were working on a study to better understand the formation of the Andes mountain range. The dinosaurs name honors Suarez and the country where the remains were found.
The fossils date to the Jurassic period, roughly 145 million years ago and the find is unusual in more ways than one. Although Chilesaurus diegosuarezi was a plant eater but was closely related to the Tyrannosaurus rex. It comes from the theropod group which also included Velociraptor, Carnotaurus in addition to Tyrannosaurs.
This is the group from which scientists believe birds evolved but is the early example of a herbivore in the group.
Palaeontologists are calling the newly discovered dinosaur a ‘platypus’ because it has an unusual combination of characteristics which seem to belong to other known dinosaurs, otherwise known as “evolutionary convergence“. In fact, early on in the process researchers thought that they had found a collection of bones from a variety of different animals.
However, since the initial discovery, more than four complete skeletons and a dozen complete Chilesaurusspecimens have been found. Most of the animals were about the size of a turkey but some measured almost 10 feet long.
The animals had feet that resembled early long-neck dinosaurs more than their famous carnivorous relatives. Because of a similar diet, Chilesaurus also had similar teeth to those of long-necked dinosaurs. It had a disproportionally small skull, robust forelimbs similar to velociraptor but without the claws on its fingers. Chilesaurus had a pelvic girdle resembles that of the ornithischian dinosaurs and a disproportionally small skull.
“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 at the University of Birmingham in a statement.
Ezcurra is one of the authors of a paper detailing the findings published in full in Nature.
In addition to its unusual anatomy, the discovery helps fill in some blanks in terms of life during the Jurrasic period in what is now Chile.
“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 Dr. Fernando Novas, Bernardino Rivadavia Natural Sciences Museum, Buenos Aires, Argentina.
