A new species of titanosaurian dinosaur called Sarmientosaurus musacchioi, who lived 95 million years ago, has just been discovered. The findings are based on a complete skull and partial neck fossil unearthed in Patagonia, Argentina.
Paleontologist Dr. Rubén D. F. Martínez, who discovered the fossil and led the study, said in a statement:
“Discoveries like Sarmientosaurus happen once in a lifetime.
“That’s why we studied the fossils so thoroughly, to learn as much about this amazing animal as we could.”
This is a special find, as titanosaurs are the largest and arguably most evolved of the sauropod dinosaurs; however their small skulls are often missing from their massive body. Using CT scanning, the stunningly preserved fossil skull has given researchers a chance to discover enticing clues about the animal’s sensory capabilities.
Matthew Lamanna study co-author and a paleontologist from the Carnegie Museum of Natural History in Pennsylvania said: “More than 60 legit titanosaur species have been named to date.” However the Sarmientosaurus is only the fourth to have an entire skull, adding:
“The head is key to understanding an animal’s biology, its home to the brain, sense organs, jaws, and teeth — food-gathering mechanisms — and more.”
Paleontologists have now an unparalleled insight into the sensory capabilities and behavior of the now named Sarmientosaurus musacchioi. It had a small-brain, good eyesight, its hearing was tuned to low frequencies, and habitually held its head with its snout facing downward, and featured a mouth full of sharp teeth, according to the paper published in the journal PLOS ONE.
According to Ohio University anatomist Lawrence Witmer, an expert on cranial anatomy:
“The Sarmientosaurus skull is beautifully-preserved, which meant that we could tease out a ton of information. It was really exciting for us to work through the CT scan data because it gave us a glimpse into the biology and lifestyle of this animal like we rarely get with dinosaurs.
“As for its brain, Sarmientosaurus, bless its heart, was not the sharpest tooth in the jaw.
“Sauropod dinosaurs in general are famous for having the smallest brain size relative to body size, and Sarmientosaurus was no exception. Its brain was about the size of a lime yet its body weighed as much as two or three elephants.”
Sarmientosaurus was 40 to 50 feet long (12-15 meters) and weighed 8 to 12 tons. It belongs to the group called titanosaurs, which were plant-eating dinosaurs known for long necks, long tails, and enormous bodies.
The Sarmientosaurus hearing organ was long, which indicates good hearing over long distances of low-frequency sounds transmitted over long distances. Their eye sockets and eyeballs were somewhat large which suggest their vision was particularly important.
The orientation of the inner ear points toward the Sarmientosaurus, that had a nose-down head posture, indicating that it most likely fed mostly on ground plants rather than cropping leaves from tall trees, Witmer said.
The Sarmientosaurus certainly did not have a lot of brain matter, with Witmer adding:
“Sarmientosaurus certainly was no Einstein and was governed mostly by instinct. It probably had enough intelligence to have some fairly complicated behaviors, but this was not a clever animal by any means.”