|“||There it is, the biggest land predator ever in South America: Giganotosaurus.||„|
| — Allen Johnson, about Giganotosaurus|
in Land of Giants
Giganotosaurus ( meaning "Giant Southern Lizard") was a genus of giant, predatory, South American carcharodontosaurid dinosaur that lived during the Early Cretaceous period. It was one of the largest terrestrial carnivores known, measuring 14 meters long, standing over 5 meters tall, and weighed 6–7 tonnes. Only Tyrannosaurus Rex is larger, at a maximum of 15 meters long and 7 tonnes.
Giganotosaurus lived in South America during the Early to Middle Cretaceous period from 127–95 million years ago. It was the top predator of its time and hunted just about anything in its environment, from as small as Iguanodon to as large as Argentinosaurus. Ever since it was first discovered in 1993, most Giganotosaurus fossils have been found in parts of South America where Argentina is today.
Although almost as large as Tyrannosaurus Rex but slightly larger then Spinosaurus, Giganotosaurus was the biggest and alpha predator of its time and region. These were massive carnivorous dinosaurs, as they stood 16–18 feet (4.9–5.5 m) tall, measured 43–46 feet (13.2–14.2 m) in length, and weighed up to roughly 6–7 tons in weight, making Giganotosaurus one of the largest predatory dinosaurs that ever walked planet Earth, second after T. rex itself.
In addition, Giganotosaurus looked very similar to the Jurassic predator Allosaurus, despite the fact that Giganotosaurus was even larger and stronger. It had a large body which ended in a long tail. It had a short neck with a large head. Its jaws were lined with long, serrated teeth designed to slice flesh. On the top of its head, above its eyes, was a small head crest. It had two relatively long arms with three digits per hand, each ending in a long, sharp curved claw. It also had a pair of long legs.
Giganotosaurus was depicted as being mostly brown with a white underbelly. Its crest was dark green. Its legs had black spots running down the femur and white stripes along the tibia.
Like many predators, Giganotosaurus was apparently pack hunter, living and hunting in numbers of five or six individuals. However, Giganotosaurus was also a solitary hunter. At least some were known to stray from the pack and go off hunting on their own for prey individually. On their own, they would be able to hunt some of the smaller animals in its ecosystem such as an Iguanodon and other small animals. A single Giganotosaurus would have a lot of trouble taking down a fully grown Argentinosaurus by itself.
Hunting in a pack enabled Giganotosaurus to tackle with larger prey, even ones as big as dinosaurs like Argentinosaurus, which were the biggest herbivores in Giganotosaurus's environment. Once they brought down and fed on an Argentinosaurus, even if it was a young Argentinosaurus, the Giganotosaurus pack wouldn't need to feed again for at least a few months.
These big dinosaur predators, they waited for the herbivores, just like crocodiles waiting at river crossings in Africa. Generally, upon finding or seeing prey, Giganotosaurus would head to the prey, catch it in its jaws and immediately devour it.