Fossils of last long-necked, duck-billed dinosaur found in Patagonia, Argentina

(CNN Spanish) — Researchers from Argentina’s National Scientific and Technical Research Council (Conicet) announced the discovery of the remains of an unknown species of long-necked herbivorous dinosaur in the province of Neuquén in the south of the country.

The discovered species were named Sidersaura Mara, according to a Coniset publication. It was characterized by its large duck-like snout and its spinal bones filled with air spaces.

Sidersaura was a rebaquisaurid dinosaur. This species was not distinguished by its large size, but it is the largest species of the family with an estimated weight of 15 tons and a length of 18 to 20 meters.

According to the paleontologists in charge of the research, one of the characteristics that distinguish this group from the rest is the star-shaped shape of its hamal arches, which are the tail bones. Another feature is the strong bones of its skull, unlike the fossils of its closest relatives.

In a publication in the journal Historical Biology, the scientists detailed that the new dinosaur species was quadrupedal and had a long tail.

The fossils found correspond to four different specimens. They were in an area known as Cañadón de Las Campanas, located 20 kilometers from Villa El Chocón in Neuquén.

Paleontological remains include the sacral region and partially articulated vertebrae of the tail, bones of the hind limbs, parts of the skull and loose vertebrae of the tail.

The rocks where the fossils were found form the Huinkul Formation, which dates to the Upper Cretaceous period and is estimated to be 96 to 93 million years old.