Artist Rendering Dreadnoughtus schrani
September 5, 2014

Massive New Species Of Titanosaur Discovered In Argentina

Chuck Bednar for redOrbit.com - Your Universe Online

A gigantic and remarkably complete dinosaur skeleton belongs to a new species that was 85 foot long and weighed a reported 65 tons during its lifetime, according to new research appearing in the September 4 online edition of the journal Scientific Reports.

The creature, which has been named Dreadnoughtus schrani is the largest land animal for which a body mass can be accurately calculated, the US National Science Foundation (NSF) explained on Thursday. Furthermore, its skeleton is exceptionally complete, with more than 70 percent of bone types (excluding the head) represented, the NSF added.

[Watch the Video: Dreadnoughtus: A Dinosaur Discovery ]

Dreadnoughtus schrani was astoundingly huge,” paleontologist Dr. Kenneth Lacovara, an associate professor in the Drexel University College of Arts and Sciences and a member of the team that discovered the fossils at a site in southern Patagonia, said in a statement.

“It weighed as much as a dozen African elephants or more than seven T. rex,” he added. “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.”

In fact, Brian Switek of National Geographic said the dinosaur would have been heavier than a Chieftain FV4201 tank, and the study authors claim it would have been “nearly impervious to attack” from predators. Dreadnoughtus was a titanosaur, meaning that it was a large herbivore with a small head and long neck, and it most likely lived between 84 million and 66 million years ago, he added.

“What makes Dreadnoughtus a remarkable new addition to this prehistoric family is the amount of material recovered from the dinosaur,” Switek explained. “The remains, representing two individual animals, include both the humerus and femur of Dreadnoughtus.” Lacovara and a team of experts from the US and Argentina measured the circumferences of those bones and used them to estimate the weight of the new species.

The fossils used in the identification of the new species were excavated of the course of four field seasons from 2005 through 2009 by Lacovara, Lucio M. Ibiricu of the Centro Nacional Patagonico in Chubut, Argentina, Matthew Lamanna of the Carnegie Museum of Natural History, and Jason Poole of the Academy of Natural Sciences of Drexel University, as well as a team of other former and current Drexel students and other collaborators, the NSF said.

Among the bones unearthed during those sessions were an over three-foot long neck vertebra, a thigh bone roughly as tall as a human male, and ribs the size of planks, said Ian Sample, science editor with The Guardian. Its bones represent the most complete skeleton of a titanosaur ever recovered, and the massive size of the Dreadnoughtus schrani led it to be named in honor of the dreadnought battleships.

Drexel University reports that more than 100 different elements of the creature’s skeleton are represented from the sample, including most of the vertebrae from its 30-foot-long tail, the neck vertebra, scapula, multiple ribs, toes, a claw, a small section of jaw and a single-tooth, as well as most of the forelimb and hind limb bones and a humerus.

The loss of the skull is fairly common in large plant-eaters, Sample explained, since the skull bones tended to be relative small and light enough to allow the dinosaur to lift its head. Along with the Dreadnoughtus schrani fossils, the team also unearthed less-complete remains to a second, smaller titanosaur at the site, the university added.

-----

What If?: Serious Scientific Answers to Absurd Hypothetical Questions by Randall Munro