Dreadnoughtus is a genus of titanosaurian sauropod dinosaur containing a single species, Dreadnoughtus schrani. D. schrani is known from two partial skeletons discovered in Upper Cretaceous (Campanian to Maastrichtian; approximately 84–66 Ma) rocks of the Cerro Fortaleza Formation in Santa Cruz Province, Argentina. It is one of the largest terrestrial vertebrates known, possessing the greatest mass of any land animal that can be calculated with reasonable certainty. D. schraniis known from a more complete skeleton than any other gigantic titanosaurian.
Drexel University paleontologist Kenneth Lacovara, who discovered the species, chose the name Dreadnoughtus, which means “fears nothing", stating “I think it’s time the herbivores get their due for being the toughest creatures in an environment."[1]
American palaeontologist Kenneth Lacovara[2] discovered the remains in the Cerro Fortaleza Formation in Santa Cruz Province, Patagonia, Argentina in 2005. Due to the large size of the bones and the remote location where they were found, it took his team four austral summers to fully excavate the remains. Mules, ropes and many team members were needed to finally get the field-jacketed bones to a truck.
In 2009, the fossils were transported to Philadelphia via an ocean freighter for preparation and study. Fossil preparation and analysis occurred at Drexel University, the Academy of Natural Sciences of Drexel University and the Carnegie Museum of Natural History. Dreadnoughtus schrani fossils will be returned to their permanent repository at the Museo Padre Molina in Rio Gallegos, Argentina.[when?]
The bones of both Dreadnoughtus specimens were scanned with a NextEngine 3D laser scanner.[3] Using the software Autodesk Maya, the scans of each bone were positioned in 3D space to create a digital articulated skeleton, which was then converted into 3D PDF files using the software GeoMagic. The high fidelity of these scans allowed Lacovara et al. (2014) to study the heavy fossils of Dreadnoughtus schrani in a way that was safe for the fossils and enhanced virtual and long-distance collaboration.
The holotype specimen, MPM-PV 1156, consists of a partial skeleton, somewhat preserved in its original layout, that comprises: a maxilla (jaw) fragment; a tooth; a posterior cervical vertebra; cervical ribs; multiple dorsal vertebrae and dorsal ribs; the sacrum; 32 caudal vertebrae and 18 haemal arches (bones from the tail) that include a sequence of 17 anterior and middle caudal vertebrae and their corresponding haemal arches found in their original layout; the left pectoral girdle and forelimb minus the front foot; both sternal plates; all pelvic elements; the left hind limb lacking a hind foot and right tibia; metatarsals I and II; and one claw from digit I.