Puertasaurus is a genus of titanosaurid sauropod that appeared during the Late Cretaceous. It lived in what is now Patagonia. The type species, Puertasaurus reuili, is named in honor of Pablo Puerta and Santiago Reuil, the co-discoverers in January 2001 of the specimen. Puertasaurus is based on a partial spinal column: a neck vertebra, a dorsal (back) vertebra, and two tail vertebrae.
One of the paleontologists who described Puertasaurus reuili, estimated that the new species was approximately 35 to 40 meters (115 to 131 ft) long and weighed between 80 and 100 metric tons (88 to 110 short tons). If correct, this would place it as one of the biggest dinosaurs (and the biggest titanosaur) ever to walk the earth, though rivaled in size by the more primitive Argentinosaurus. It would also extend the period of time in which such very large sauropods lived; this species roamed what is now Patagonia towards the end of the Cretaceous period, some 70 million years ago, in the early Maastrichtian.
Puertasaurus belonged to the clade Titanosauria. Based on the shape of its known vertebrae, it is most closely related to the lognkosaurians, a transitional group within Titanosauria which includes the gigantic Futalognkosaurus and the somewhat smaller Mendozasaurus, known for their hefty necks and wide rib cages, as well as similar wing-like diapophyses. If it is a lognkosaurian, Puertasaurus would be not only the largest but also the last known member of the group. Lognkosaurians were common in the Turonian and Coniacian epochs, but Puertasaurus lived in the Maastrichtian, the very last stage of the Late Cretaceous, when the much smaller Saltasaurids were the most common titanosaur group.
Credit to wikipedia for the article.