Giganotosaurus, one of the largest carnivorous dinosaurs, lived during the Late Cretaceous period, approximately 100 to 97 million years ago. Its name, meaning “giant southern lizard,” reflects its immense size, with individuals reaching lengths of 12 to 13 meters (40 to 43 feet) and weighing between 7,000 and 8,000 kilograms (15,400 to 17,600 pounds). With a large skull and dozens of serrated teeth up to 20 centimeters (8 inches) long, Giganotosaurus was a powerful predator, likely preying on large herbivorous sauropods. Fossil finds of such large ancient creatures are rare.
The First Giganotosaurus Discovery
The primary discovery of Giganotosaurus occurred in 1993, when amateur fossil hunter Rubén D. Carolini found a tibia bone in the Candeleros Formation of Neuquén Province, Patagonia, Argentina. Paleontologists from the National University of Comahue excavated the site. This specimen, designated MUCPv-CH-1, was approximately 70% complete.
The recovered bones included parts of the skull, pelvis, leg bones, and most of the vertebral column. The skull alone measured an estimated 1.53 to 1.80 meters (5.0 to 5.9 feet) in length. In 1995, paleontologists Rodolfo Coria and Leonardo Salgado described the new species, naming it Giganotosaurus carolinii in honor of its discoverer.
Other Giganotosaurus Remains
A second confirmed Giganotosaurus fossil represents another individual. This find consists of a partial left dentary bone, part of the lower jaw, along with a tooth. The jaw bone, labeled MUCPv-95, was found in 1987 near Lake Ezequiel in Argentina.
Initially, this fragmentary material was not definitively attributed to Giganotosaurus, having been briefly described in 1989. However, it was assigned to the genus in 1998 by paleontologists Jorge O. Calvo and Coria. This second jaw bone is approximately 8% larger than the corresponding bone from the holotype specimen, suggesting it belonged to an even larger individual. These two individuals represent the primary Giganotosaurus fossil evidence, with other findings limited to isolated teeth or small bone fragments.
Why Complete Dinosaur Skeletons Are Rare
The limited number of Giganotosaurus finds reflects the challenges inherent in the fossilization process. For an animal’s remains to become a fossil, specific and rare conditions must align, beginning with rapid burial after death. This quick covering protects the body from scavengers, decomposition by bacteria, and weathering.
Many factors work against this preservation. Scavengers and other predators often scatter bones, while natural elements like flowing water and wind can break apart or disperse a skeleton before burial. Even if buried, the surrounding environment must have the correct chemical conditions for minerals to replace organic material, preventing decomposition.
Geological upheavals over millions of years can further disrupt or destroy fossilized remains, making their discovery even more improbable. Finding even partial dinosaur skeletons is an exceptional event.