Giganotosaurus

Overview

Giganotosaurus carolinii was a colossal theropod dinosaur inhabiting forested plains of what is now South America during the Late Cretaceous. Often compared to Tyrannosaurus rex in size, Giganotosaurus could reach lengths of around 43 ft (13 m) and weigh up to 8 tons. Fossil evidence suggests it may have hunted large herbivores—possibly Argentinosaurus and other titanosaurs—and may have done so in small groups.

This apex predator possessed powerful jaws and serrated teeth designed for slicing flesh. Its name means “giant southern lizard,” reflecting not only its massive proportions but also its geographic origins in modern-day Argentina.

Quick Facts

Diet

Carnivore (large dinosaurs)

Speed

~20 mph (est.)

Weight

~8 tons

Length

~43 ft (~13 m)

Bite Force

~11,000 psi (estimated)

Discovery & Significance

Giganotosaurus was first named and described in 1995 by paleontologists Rodolfo Coria and Leonardo Salgado, based on fossils unearthed in Argentina’s Neuquén Province. The discovery fueled debates over which theropod held the title of largest land predator. While close in size to T. rex, Giganotosaurus appears to have had a lighter build and longer skull.

Studies of Giganotosaurus underscore the evolutionary success of large carcharodontosaurids in the southern continents, diverging from the tyrannosaur-dominated ecosystems in North America. Fossil evidence suggesting potential group hunting behavior points to advanced strategies for taking down giant herbivores—making Giganotosaurus one of the most formidable predators of its time.

Giganotosaurus vs. Other Giant Theropods

More Details

One of the largest known carnivorous dinosaurs of the Late Cretaceous period is Giganotosaurus, discovered in 1993 in Argentina’s Candeleros Formation. Its name means “giant southern lizard,” honoring both its impressive size and the continent where it was found. The holotype skeleton is around seventy percent complete, which has helped researchers estimate its length at approximately 12 to 13 meters (39 to 43 ft) and a possible weight between 4.2 and 13.8 metric tons. One larger jaw fragment hints at an individual exceeding even these numbers, sparking ongoing debate about whether Giganotosaurus surpassed Tyrannosaurus in sheer size. Compared to its close relatives, this predator boasted a relatively low and elongated skull, up to 1.53 meters (5.0 ft) long in the known holotype, although some scholars suggest it could have reached 1.80 meters (5.9 ft). Its jaws contained serrated teeth that were flattened side to side, adept for slicing through flesh, and the tip of its lower jaw formed a peculiar “chin” that might have helped absorb stress during bites. Paleontologists have proposed that Giganotosaurus could bite quickly to subdue large prey, though its jaw strength may have been less suited for crushing bone than that of tyrannosaurids. Evidence places Giganotosaurus within the Carcharodontosauridae family, making it kin to other giant theropods such as Mapusaurus, Tyrannotitan, and Carcharodontosaurus. These dinosaurs were likely apex predators in their ecosystems; Giganotosaurus may have hunted or scavenged huge sauropods, possibly targeting juveniles in a land dominated by massive plant-eaters. Some studies propose it had a homeothermic metabolism (an intermediate type of “warm-bloodedness”) that supported rapid growth and an active lifestyle. While its exact maximum size remains unresolved, Giganotosaurus stands as an imposing symbol of the incredible diversity and scale of South America’s Cretaceous predatory dinosaurs—an apex hunter that may have rivaled, or even surpassed, the most iconic giants of the Mesozoic world.

References & Further Reading