Argentinosaurus

Argentinosaurus (meaning "Argentine lizard") is a genus of titanosaur sauropod dinosaur first discovered by Guillermo Heredia in Argentina. The generic name refers to the country in which it was discovered. The dinosaur lived on the then-island continent of South America somewhere between 97 and 94 million years ago, during the Late Cretaceous Epoch. It is among the largest known dinosaurs.

Not much of Argentinosaurus has been recovered. The holotype included only a series of vertebrae (six from the back, five partial vertebrae from the hip region), ribs of the right side of the hip region, a part of a rib from the flank, and the right fibula (lower leg bone). One of these vertebra was 1.59 meters tall, and the fibula was about 1.55 meters (58 inches). In addition to these bones, an incomplete femur (upper leg bone, specimen number MLP-DP 46-VIII-21-3) is assigned to Argentinosaurus; this incomplete femur shaft has a minimum circumference of about 1.18 meters. The proportions of these bones and comparisons with other sauropod relatives allow paleontologists to estimate the size of the animal.