Found on a small Japanese island more than a decade earlier, the remains of a strange herosaur had recently been subjected to thorough examination, revealing that it was a whole new species.

An atypical profile

In 2004, an amateur fossil hunter discovered the lower jaw, teeth, cervical vertebrae, as well as from the shoulders and bones of the island to the tail of a dinosaur.Avaji. Trapped in sediment for nearly 72 million years, fossil remains were returned Japanese Museum of Nature and Human Activities. As part of the work presented in the magazine Scientific report, The researchers carried out their detailed analysis and found that they belong to a new species as well as a new species of Hrasosaurs, called Yamatosorus izanagii.

Recognized by their wide, flattened muzzle, reminiscent of the beak of a duck, Hrasosaurus was a vegetarian creature that lived during the Late Cretaceous more than 65 million years ago. According to the researchers, their ability to chew the vegetation was one of the main factors that allowed the diversity, abundance, and generalization of their populations on the planet.

Although many fossils have been discovered on most continents in recent decades, the discovery Yamatosorus Researchers have looked at the ideas of Hadoosaurs so far. Fossil analysis revealed an unusual dental structure, suggesting a different diet.

« Hedrosaurus had hundreds of teeth very close to each other. As their teeth grinded and fell out, new rows under the existing teeth grew to replace them. “, Please explain Anthony FiorilloResearcher atSouthern Methodist University And co-authors of the study. ” Yamatosaurus’ jaw was oddly devoid of a branched crest on the chewing surfaces, with only one type of functional tooth, suggesting that it fed on vegetation different from other accidentals.. »

Searches suggesting possible migration of losers from Asia to North America

The animal was also distinguished by an unexpected level of development in the tendon and forelimbs, which marked an important stage in the evolution of the species, from a bipedal mode to a quadruple gait. According to the researchers, the discovery of this new species also raises important questions about the migration patterns of these herbivorous organisms, potentiallyAsia ByNorth America, And not the reverse.

« In the far north, Hadasaur is considered a Cretaceous caribou “, The study’s authors say. ” They probably used the Bering Land Bridge to cross from Asia to present-day Alaska, then spread to the Appalachians in North America.. »