by A team of paleontologists from Conicet and several museums presented to society the discovery of a new species of dinosaur found in the soil of Neuquen. Is about Sidersaura marae, a long-necked, duck-billed animalone of the largest of its species, which lived more than 90 million years ago.
The team found the fossil remains of four Sidersaura specimens in Cañadón de Las Campanas, a town located 20 kilometers from Villa El Chocón, in the province of Neuquén. It’s about a rebaquisaurid (rebbachisauridae) which was characterized by its wide snout like that of a duck, which made it easier for it to feed on low vegetation, and by the bones of its spinal column filled with spaces with air (like birds), which gave it a much lower weight than expected.
Sidersaura was quadruped, had a long tail and, although the rebaquisaurids were not distinguished by their large size, it was the largest species of the family, with an estimated mass of 15 tons and a length of between 18 and 20 meters.
“It is one of the largest animals in its group”, describes it Sebastián Apesteguía, Conicet researcher and director of the Paleontology Area of the Félix de Azara Natural History Foundation. As he explains, its duck bill as an edger would allow it to feed on ground vegetation. “They are animals that they were eating all the time“, he continued in a talk with TN.
Apestiguia stressed that bringing the specimen to light required some five years of work. “The rebaquisaurids were dinosaurs very important in Cretaceous ecosystems. “They disappeared in the middle of that period in a mass extinction event that took place 90 million years ago, in which carcharodontosaurids, the largest carnivorous dinosaurs in the world, also became extinct,” he added.
The rocks of the Huincul Formation, which emerge in the location of the discovery, correspond to the beginning of the Upper Cretaceous and have an estimated age of between 96 and 93 million years.
“Sidersaura is one of the last rebaquisaurids, but at the same time it belongs to an ancient lineage in evolutionary terms; This shows us that, at the end of their time, some of the rebaquisaurids survived. of the early times, and that these were among the largest of their group, given that they could reach nearly 20 meters in length,” he highlighted.
The researchers determined that these dinosaurs died in a muddy area near a river and his remains decomposed in that same place.
Then, scavengers took away some bones and the river floods washed away other remains and partially dismantled the skeletons.
For his part, the Conicet doctoral fellow at the Center for Natural, Environmental and Anthropological Sciences of the Maimónides University, Lucas Lerzo, pointed out that “having several specimens that overlap anatomically allowed us to correlate them and better understand the characteristics of this new dinosaur.” “. sauropod”.
One of the characteristics that distinguish Sidersaura from other dinosaurs is the stellate shape of their hemal arches (tail bones).
“This particularity is what gives the species its name, given that ‘sider’ It means star in Latin,” Lerzo said.
Among the bone remains recovered from Sidersaura is also the calcaneus, one of the two bones that make up the ankle of terrestrial vertebrates, along with the talus, which until now had not been found in known rebaquisaurids.
In this case, the researchers interpret that the morphology of this bone gave it greater resistance when passing to the hind limb.
From Conicet they stated that the study carried out indicates that Sidersaura is related to the African rebaquisaurid Nigersaurus taqueti, which had a notable widening of the jaw and a prominent dental battery.
The work was funded by National Geographic, the Municipality of Villa El Chocón, the Azara Foundation and the Field Museum of Natural History in Chicago.
