After 83 Million Years, Scientists Decode the Identity of a Small, Big-Eyed Patagonian Dinosaur

Gasparinisaura cincosaltensis really did have enormous eyes. For years, scientists had suspected that the feature belonged only to a juvenile specimen. A new study now indicates that the large eye sockets were a genuine anatomical characteristic of adult animals.

The finding comes three decades after paleontologists Rodolfo Coria and Leonardo Salgado announced the discovery of the small, bipedal dinosaur in September 1996. It lived about 83 million years ago in what is now Argentina's Río Negro province, during the Cretaceous period.

An international team led by researchers from Argentina's National Scientific and Technical Research Council, known as Conicet, examined a specimen from the Anacleto Formation near Cinco Saltos. The fossil contains the most complete skull yet documented for a non-hadrosauriform ornithopod in the Southern Hemisphere.

To study it without damaging the fossil, the researchers used medical computed microtomography. They digitally extracted the braincase and built a three-dimensional model, allowing them to separate the animal's original anatomy from the deformation and compression it suffered while buried for millions of years.

The work, published in Cretaceous Research, confirmed that the species belonged to the Elasmaria lineage within the Dryosauridae family. It also helped fill a scientific gap of nearly 72 million years and establish the new subfamily Dysalotosaurinae. The classification links the Patagonian species with dinosaurs found in Late Jurassic Tanzania and Middle Cretaceous Australia.