A remarkable new species of titanosaurian sauropod dinosaur being named Sarmientosaurus musacchioi has been discovered by a team of paleontologists led by Dr. Rubén Martínez at the National University of the Patagonia San Juan Bosco.
Reconstruction of Sarmientosaurus musacchioi skull. Image credit: Mark A. Klingler, Carnegie Museum of Natural History / WitmerLab, Ohio University.
Sarmientosaurus musacchioi roamed what is now Argentina approximately 95 million years ago in the Upper Cretaceous epoch, Dr. Martínez and his colleagues believe.
An exceptionally well-preserved skull and neck fossil of this new dinosaur was unearthed in the Bajo Barreal Formation of southern Chubut Province, central Patagonia.
According to the scientists, Sarmientosaurus musacchioi is the first titanosaurian sauropod from southern South America for which a virtually complete adult skull has been discovered.
Using CT scans, they found that the Sarmientosaurus brain was small relative to its enormous body, typical of sauropod dinosaurs.
However, they also found evidence of greater sensory capabilities than most other sauropods.
“Sarmientosaurus musacchioi possesses a number of distinctive features that have not been observed in other sauropods,” the paleontologists said.
“The cranial endocast presents among the most complete information about the brain and sensory systems for any sauropod, let alone titanosaurs, and thus will be important for the developing picture of neural evolution in Sauropoda.”
They suggest that this titanosaur had large eyeballs and good vision, and its inner ear may have been better tuned for hearing low-frequency airborne sounds compared to other titanosaurs.
Moreover, the balance organ of the inner ear indicates that this dinosaur may have habitually held its head with the snout facing downward, possibly to feed primarily on low-growing plants.
“Discoveries like Sarmientosaurus musacchioi happen once in a lifetime,” said Dr. Martínez, who is the lead author of a report published this week on Sarmientosaurus musacchioi in the journal PLoS ONE.
“That’s why we studied the fossils so thoroughly, to learn as much about this amazing animal as we could.”
“Sarmientosaurus musacchioi is named for the town of Sarmiento in Chubut Province, which is close to the discovery site,” the scientists said.
“The species name also honors the late Prof. Eduardo Musacchio, a paleontologist at the National University of the Patagonia San Juan Bosc and friend to Dr. Martínez and other team members.”
_____
Martínez R.D.F. et al. 2016. A Basal Lithostrotian Titanosaur (Dinosauria: Sauropoda) with a Complete Skull: Implications for the Evolution and Paleobiology of Titanosauria. PLoS ONE 11 (4): e0151661; doi: 10.1371/journal.pone.0151661
