Hitherto unknown giant herbivorous dinosaur species

A new species of giant herbivorous dinosaur has been discovered after analyzing some fossil remains.

Argentina could be known as “the land of dinosaurs”. And it is that throughout the country there are already many, both in quantity and in variety of species, the dinosaurs whose fossil remains have been found in the territory. However, among these numerous paleontology findings, a giant herbivorous dinosaur had never appeared in the province of Río Negro… until now.

This species of giant herbivorous dinosaur discovered in Argentine Patagonia has received the name Chucarosaurus diripienda. The individual whose fossil remains have made the discovery possible lived in the area about 90 million years ago.

Found specifically in the north of the province of Río Negro, the Chucarosaurus diripienda shows that large dinosaurs inhabited all of Patagonia.

Towards the end of 2019, a research expedition to the south of Villa el Chocón found isolated bones of enormous size and weight.

The team made up of researchers from the National Council for Scientific and Technical Research (CONICET), the Argentine Museum of Natural Sciences, the Félix de Azara Natural History Foundation and the National University of Cuyo, all of these entities in Argentina, carried out a long and thorough investigation.

The conclusion reached in the study is that it is a completely new species: the Chucarosaurus diripienda.

“When analyzing the bones found, it was possible to distinguish a large herbivorous dinosaur with a long neck. It belongs to the group of colossaurus sauropods, which means ‘colossal saurians or large reptiles’, details Federico Agnolin, paleontologist and co-author of the study. The team also includes, among others, Sebastián Rozadilla, Matías J. Motta and Nicolás R. Chimento, all three from the Laboratory of Comparative Anatomy and Evolution of Vertebrates, at the Bernardino Rivadavia Argentine Museum of Natural Sciences, dependent on CONICET.

The specimen in question had a femur of about 2 meters in height with a weight of 200 kilograms, which allowed paleontologists to calculate an approximate weight of between 40 to 50 tons and about 30 meters in length. “This makes it one of the largest known dinosaurs, rivaling the giants Argentinosaurus and Patagotitan. In any case, the known remains of the Chucarosaurus are notably lighter, which suggests that it would be much more slender than other giants”, Agnolin specifies, in dialogue with the CTyS-UNLaM Agency.

Recreation of the approximate appearance that an adult specimen of Chucarosaurus diripienda should have looked like in life. (Illustration Sebastian Rozadilla)

The Chucarosaurus was discovered along with a large amount of plant remains, including fossil trunks, in rocks that indicate that there was once a river. Nearby, the researchers also found remains of a huge predatory dinosaur known as the Taurovenator.

These indications, explains Agnolin, allow paleontologists to obtain an “instantaneous” photograph of the north of Rio Negro some 90 million years ago, with a Chucarosaurus inhabiting a wooded environment, on the banks of a river and attentive to the different predators of the time. .

About 90 million years ago, northern Patagonia was very different from how it is known today. What today are arid plateaus with thorny bushes and a scorching sun, back then were covered by endless araucaria forests, dotted with lakes, lagoons and rivers.

After finding, extracting, and preserving the Chucarosaurus bones, the team of paleontologists set out to leave the Pueblo Blanco Nature Reserve, located 25 kilometers south of Villa el Chocón. But, in the process of transferring the bones, something unexpected happened.

“We had carefully loaded all the Chucarosaurus bones into the back bed of the truck,” Agnolin recounts. Already on the trip, the fossils were so heavy that they unbalanced the truck, which caused the vehicle to overturn. Fortunately, no investigators were injured and although the bones were scattered on the ground, they were not damaged.

When a paleontological find is made, its discoverers have the possibility to choose the name with which the scientific world will refer to that specimen. The team that makes up Agnolin did not have much to think about: it was a large, resistant dinosaur that had caused quite a stir during the transfer of its remains.

“Scientifically we baptize it as Chucarosaurus diripienda. The first name refers to the resistance and strength of the bones, which weigh more than 100 kilos each. The second means ‘scrambled’ in reference to the accident during its transfer”, concludes Agnolin, a member of the Argentine Paleontological Association, which thus adds another species to the rich collection of dinosaurs found in local lands.

The study is titled “A new giant titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of Northwestern Patagonia, Argentina”. And it has been published in the academic journal Cretaceous Research. (Source: Magalí de Diego (CTyS-UNLaM Agency))