72 million-year-old fossils of new duck-billed dinosaur species discovered in Chile

The bones were determined to be of a new species of dinosaur with flattened, waterfowl-like snouts. Many body parts were retrieved, including hips, limbs, ribs, vertebrae, and a head, from the site. Gonkoken nanoi is noted to be the fifth species of dinosaur identified in Chile. 

The older lineage of the duck billed-dinosaur 

The findings revealed that the new species existed in what is now South America long before hadrosaurids, also known as advanced duckbills.

The authors emphasize that Gonkoken was most likely an older lineage that split from other duck-billed dinosaurs approximately 91 million years ago — much before the first hadrosaurids came into life. 

Another revelation was that hadrosaurs may have sought sanctuary in Chilean Patagonia during the Cretaceous period (145 to 66 million years ago). The most recent finding of this duck-billed dinosaur species reveals hadrosaurids were not as geographically distributed as once speculated.

"Our discovery clarifies there is no conclusive evidence that hadrosaurids ever reached as far as southern Patagonia and Antarctica. Instead, the only reliable evidence this far south is for the presence of a different, older lineage of duck-billed dinosaurs," said Alexander Vargas, a paleontologist at the Universidad de Chile and one of the study's corresponding authors.

The authors plan to create a 3D reconstruction of the skeleton remains of Gonkoken.

The results have been reported in the journal Science Advances. 

Study abstract:

In the dusk of the Mesozoic, advanced duck-billed dinosaurs (Hadrosauridae) were so successful that they likely outcompeted other herbivores, contributing to declines in dinosaur diversity. From Laurasia, hadrosaurids dispersed widely, colonizing Africa, South America, and, allegedly, Antarctica. Here, we present the first species of a duck-billed dinosaur from a subantarctic region, Gonkoken nanoi, of early Maastrichtian age in Magallanes, Chile. Unlike duckbills further north in Patagonia, Gonkoken descends from North American forms diverging shortly before the origin of Hadrosauridae. However, at the time, non-hadrosaurids in North America had become replaced by hadrosaurids. We propose that the ancestors of Gonkoken arrived earlier in South America and reached further south, into regions where hadrosaurids never arrived: All alleged subantarctic and Antarctic remains of hadrosaurids could belong to non-hadrosaurid duckbills like Gonkoken. Dinosaur faunas of the world underwent qualitatively different changes before the Cretaceous-Paleogene asteroid impact, which should be considered when discussing their possible vulnerability.