A newly-discovered dinosaur that represents the largest land animal that's body mass can be accurately calculated thanks to an exceptionally complete skeleton discovered in Argentina.
The skeleton contains over 70 percent of its bones, minus the head. The dinosaur was believed to be 85 feet long and weighed about 65 tons, Drexel University reported.
"Dreadnoughtus schrani was astoundingly huge," said Kenneth Lacovara, PhD, an associate professor in Drexel University's College of Arts and Science. "It weighed as much as a dozen African elephants or more than seven T. rex. Shockingly, skeletal evidence shows that when this 65-ton specimen died, it was not yet full grown. It is by far the best example we have of any of the most giant creatures to ever walk the planet."
The researchers discovered and described the new species, which has the most complete skeleton or its kind. The dinosaur is a member of a group of plant eaters called titanosaurs. The paper described features such as: "the 30-foot-long tail, a neck vertebra with a diameter of over a yard, scapula, numerous ribs, toes, a claw, a small section of jaw and a single tooth, and, most notably for calculating the animal's mass, nearly all the bones from both forelimbs and hindlimbs including a femur over 6 feet tall and a humerus," Drexel University reported.
"Titanosaurs are a remarkable group of dinosaurs, with species ranging from the weight of a cow to the weight of a sperm whale or more. But the biggest titanosaurs have remained a mystery, because, in almost all cases, their fossils are very incomplete," said the Carnegie Museum of Natural History's Matthew Lamanna.
The team used digital modeling to create a three-dimensional reconstruction. Laser scans revealed extremely well-preserved muscle attachment scars that provide important information about biological function. The name "Dreadnoughtus" means "fears nothing" because of its immense size and weaponized tail.
"I think it's time the herbivores get their due for being the toughest creatures in an environment," Lacovara said.
To grow as large as it did the dinosaur would have had to consume massive amounts of plants, causing them to devote their entire lives to eating.
"Every day is about taking in enough calories to nourish this house-sized body. I imagine their day consists largely of standing in one place," Lacovara said. "You have this 37-foot-long neck balanced by a 30-foot-long tail in the back. Without moving your legs, you have access to a giant feeding envelope of trees and fern leaves. You spend an hour or so clearing out this patch that has thousands of calories in it, and then you take three steps over to the right and spend the next hour clearing out that patch."
The species was described in the journal Scientific Reports.
