An Ultimate Guide to Giganotosaurus: Giant Southern Lizard

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Name Meaning“Giant Southern Lizard”Height5 to 5.5 meters (16.6 to 18.3 ft.)
PronunciationGee-gah-note-oh-sore-usLength13.7 meters (45 ft.)
EraMesozoicLate CretaceousWeight8 to 10 tons (8.8 to 11 short tons)
ClassificationDinosauria, Saurischia & TheropodaLocationArgentina (South America)

Giganotosaurus Pictures

Giganotosaurus | Warpaintcobra via Getty Images

The Giganotosaurus

Gage Beasley Prehistoric's Giganotosaurus Concept
Gage Beasley Prehistoric’s Giganotosaurus Concept

In Earth’s history, there have been giant animals that tower over the modern species we see today, and one of the largest carnivores to ever walk the Earth is Giganotosaurus.

It lived in what is now Argentina during the Late Cretaceous period and was discovered in the Candeleros Formation in 1993.

The holotype specimen of Giganotosaurus is around 70% complete, and while this fossil helped us learn more about large theropods, it also left many questions.

As a member of the Carcharodontosauridae family, it is related to other dinosaurs like Mapusaurus, and Carcharodontosaurus

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Gage Beasley’s Prehistoric Shirt Collection
Gage Beasley's Prehistoric Plush Collection
Gage Beasley’s Prehistoric Plush Collection

Giganotosaurus is one of the largest land carnivores to ever roam the earth, but the size of this dinosaur has been heavily debated.

Due to the incomplete specimens, many traits about this dinosaur like their maximum size, and head shape may change in the future if more fossils are discovered.

In this article, you will learn the amazing things paleontologists have managed to discover about Giganotosaurus, and what questions still remain.

Physical Characteristics

Gage Beasley Prehistoric's Giganotosaurus Size Comparison Chart
Gage Beasley Prehistoric’s Giganotosaurus Size Comparison Chart

Giganotosaurus is believed to be one of the largest theropods to ever exist, and like other similar dinosaurs had large heads, small arms, walked on two legs, and had a large tail to help them balance.

It had an estimated length between 12 to 13 meters (39 to 43 ft.), and had a large skull that ranged between 1.53 to 1.80 meters (5 to 5.9 ft.) in length.

In the large jaws of Giganotosaurus, this dinosaur had around 76 teeth, and each curved tooth measured around 20.32 cm. (8 in.) in length.

It has been estimated to be around 5 to 5.5 meters (16.6 to 18.3 ft.) tall, and its weight estimates varied from 4,200 to 13,607 kgs. (9,300 lbs to 30,000 lbs).

Gage Beasley Prehistoric's 3D Giganotosaurus Concept
Gage Beasley Prehistoric’s 3D Giganotosaurus Concept

The size of the Giganotosaurus compares with some of the largest meat-eating dinosaurs ever to exist, which include:

The main reason there has been confusion about the size is due to the fossils discovered, as many of them are fragmented, and the specimen’s ages are unknown.

As more fossils are continued to be discovered paleontologists will continue to attempt to accurately estimate their size. 

Habitat and Distribution

Giganotosaurus lived during the Cretaceous period in Argentina, as well as other regions in South America.

This dinosaur lived in the Early Cenomanian age around 99.6 to 97 million years ago.

The discovery of Giganotosaurus occurred in the Candeleros Formation, and this formation has been essential in learning about the ecosystem this dinosaur lived in. 

It inhabited warm and lush forest habitats with wetlands and floodplains. 

The Cretaceous period in South America had lots of plants, some of which could be found in the water.

A Dutchman’s pipe flower hangs from the vine showing off its beauty. | SHAWSHANK61 via Getty Images

South America was a lush environment in the Cretaceous period that contained plants such as:

  • Horsetails
  • Ferns
  • Ginkgo
  • Dutchman’s Pipe
  • Cycads
  • Cattail
  • Water Cabbage
  • Green Microalgae
  • Lotuses

Due to the large herbivores that Giganotosuarus fed on South America had lots of plant life.

Fossil evidence in the Candeleros Formation suggests South America had lots of rivers, and wetlands, and was very fluvial. 

South America during the Cretaceous period was very warm, and had a seasonality of heavy rainfall, with the environment being very similar to the one today.

Behavior and Diet

Several ceratopsian dinosaurs run for their lives when a Giganotosaurus comes after them | CoreyFord via Getty Images

Giganotosaurus is one of the largest meat-eating dinosaurs to walk the earth, and in their habitat of Argentina were likely the apex predator. 

Its size made it capable of killing any dinosaur they came across, and paleontologists believe this dinosaur had a diet made up of herbivorous dinosaurs

The large size of Giganotosaurus let them easily overpower other dinosaurs, and their sharp teeth allowed them to bite through the thick hides of their prey.

A look at the partial skull found gave insight into how these dinosaurs ate.

Partial holotype skull (white parts are reconstructed), EBPM | Neloadino via Wikipedia (CC BY-SA 4.0)

Their fossils suggest the lower jaws of this dinosaur were used for crushing and slicing, while their front jaws helped in manipulating prey.

It is not believed that they lived, or hunted together, and they are thought to have been solitary.

Theropods like Giganotosaurus hunting together would have helped them take out larger prey like sauropods, but there is still evidence needed to confirm if they worked together to hunt. 

Giganotosaurus’s size, and crushing jaws gave them the ability to feed on a variety of smaller animals, including juvenile sauropods, and even other theropods if given the chance. 

Life Cycle

Giganotosaurus | Racksuz via Getty Images

Giganotosaurus likely had a similar reproduction cycle with other theropods, and reproduced by laying eggs.

Fossil evidence from these dinosaurs that gives insight into their life cycle has not been discovered.

When compared with other dinosaurs that have been studied for over 100 years, it is a relatively new dinosaur.

Giganotosaurus when young would have been most vulnerable to predators, so their mothers likely guarded their young until they could defend themselves. 

Giganotosaurus | Warpaintcobra via Getty Images

Studies into similar species suggest Carcharodontosauridae dinosaurs like Giganotosaurus were very slow-growing when compared to dinosaurs like Tyrannosaurids.

If similar to related species, it could take up to 30 to 40 years to fully mature and could have lived more than 50 years. 

There is still a lot to learn about these dinosaurs’ life cycle, and overall there has been little juvenile, and other growth stages of this dinosaur discovered.

Evolution and History

Holotype skeleton with reconstructed skull, arm, and feet, on the floor in Ernesto Bachmann Paleontological Museum | Simona.cerrato via Wikipedia (CC BY-SA 3.0)

Giganotosaurus was discovered in 1993 by amateur fossil hunter Ruben D. Carolini. 

Only the tibia of this dinosaur was discovered at first, found in the badlands near Villa El Chocon in Argentina, and later a team was sent out to uncover the rest of this dinosaur.

In 1995 the new species Giganotosaurus carolinii was named in honor of their discoverer. 

Giganotosaurus means “Giant Southern Lizard ”, and today there’s only one species in their genus.

It really intrigued paleontologists since their bones suggested they were as large as some of the biggest carnivorous dinosaurs to exist such as Tyrannosaurus, and Megalosaurus.

The bones of Giganotosaurus were heavier than the largest known Tyrannosaurus specimen, but due to a fragmented skull, it was difficult to depict their true size.

Reconstructed skeleton, Natural History Museum, Helsinki | Sukram-C via Flickr (CC BY-SA 2.0)

Throughout the 2000s various paleontologists have done their best to attempt to figure out Giganotosaurus size using fossils findings from other dinosaurs, and examining the bones that have been found.

In 2022 a skull of another Carcharodontosaurine Meraxes was discovered, which was the most complete skull found of these dinosaurs so far.

Using the Meraxes fossils, Giganotosaurus is estimated at having a 1.634 (5.36 ft.) long skull, and the skull also helped better estimate its size.

Theropods such as Giganotosaurus, Megalosaurus, and Tyrannosaurus are an example of convergent evolution, as these dinosaurs all evolved to grow massive, with small arms, and large heads.

Due to the many threats within the Mesozoic era being large in size would be a common evolutionary trait amongst the top predators.

Giganotosaurus went extinct around 97 million years ago, killed off during the Cretaceous-Tertiary mass extinction event which killed around 70% of all life on earth, including the dinosaurs.

Interactions with Other Species

Restoration of Giganotosaurus with contemporary dinosaurs | ABelov2014 via Deviant Art

In the Cretaceous period in South America there lived some of the largest dinosaurs to ever exist.

Giganotosaurus was the largest predator in South America and shared its environment with giants such as titanosaurs.

Some animals that lived alongside the theropod include:

  • Andersaurus
  • Limaysaurus
  • Ekrixinatosaurus
  • Buitreraptor
  • Alnashetri
  • Araripesuchus
  • Abelisaurus

The large size of Giganotosaurus would have been used to tackle prey, and their powerful jaws to kill.

Fossil evidence found together suggests these animals could have lived together in packs in Argentina, but there still needs to be more evidence to confirm this.

Giganotosaurus was a carnivorous theropod dinosaur that lived in Argentina during the Cretaceous Period. | CoreyFord via Getty Images

Whether alone or living together, Giganotosaurus were at the top of their food chain, and even when young could compete with other large theropods. 

In Cretaceous South America there were also snakes like Prochelidella and pterosaurs that it likely hunted.

As more evidence comes to light on the animals in prehistoric Argentina it will only become more clear on the swampy environment that Giganotosaurus ruled over.

Cultural Significance

Giganotosaurus skeleton mount at the Fernbank Museum of Natural History in Atlanta, Georgia | Jonathan Chen via Wikipedia (CC BY-SA 4.0)

Discovered in 1993, Giganotosaurus has grown to be one of the most beloved dinosaurs even with their recent discovery.

These dinosaurs have been featured in media like Jurassic Park, and games such as ARK, and due to these dinosaurs’ massive size it was not long until this genus became a fan favorite for many.

Giganotosaurus was also an important discovery in paleontology as it helped scientists get a better look at the overall ecosystem in Cretaceous South America.

Giganotosaurus in Jurassic World: Dominion | Photo via Jurassic Park Wiki

Very quickly many took interest in the “Giant Southern Lizard” Giganotosaurus, and today their size is still being debated.

The first fossil of Giganotosaurus was around 70% complete and their finding helped paleontologists gain a better understanding of dinosaurs in the Carcharodontosauridae family.

When thinking about South American dinosaurs Giganotosaurus is one of the most iconic, and in the future, better fossils can help us learn more about this giant. 


Even today it is still not known how large Giganotosaurus was, but these dinosaurs were definitely one of the largest carnivorous dinosaurs.

Their name alone Giganotosaurus gives some insight into the size of these giants.

Giganotosaurus due to their size were the king of South America during the Cretaceous period.

There is still a lot to learn about the “Giant Southern Lizard”, but even being a recently discovered species when compared to other dinosaurs they have gained the appreciation of many people in the paleontology, and pop culture community.

While sharing its environment with some of the deadliest dinosaurs on earth, Giganotosaurus was the apex predator that no other animal would dare to mess with.

The Cretaceous period in South America had dinosaurs, but other life-like mammals, amphibians, crocodilians, and pterosaurs that today we only know through fossils.

Earth’s history is an expansive tale, and while some animals of the past seem like fiction, they have all worked together with evolution to get the amazing animals we have today.

Giganotosaurus is one of many South American dinosaurs, and with more fossils findings and studies many of these dinosaur’s secrets may soon be revealed.


What was the bite force of Giganotosaurus?

The bite force of Giganotosaurus is estimated at 2,721 kgs (6,000 lbs.) of force per square inch.

Their powerful bite force and large size are why these dinosaurs are one of the most dangerous land carnivores to ever walk the earth.

While fossils of the Giganotosaurus are helpful in learning about this species’ bite force, it may be inaccurate since only fragments of their skull have been discovered. 

Is Giganotosaurus larger than Tyrannosaurus Rex?

The size of Giganotosaurus has been heavily debated, but their largest estimate has them larger than the T-Rex.

It had a length up to 13.7 meters (45 ft.) long, and a weight of up to 9071 kg. (20,000 lbs).

The T-Rex was slightly smaller with a length of up to 12.1 meters (40 ft.), and a weight of up to 15,500 lbs. 

How fast was Giganotosaurus?

Using the fossils and digital models of Giganotosaurus this large dinosaur has a speed estimated at 50 kph (31.3 mph).

It used its speed to chase down prey, but many smaller dinosaurs like Velociraptors are faster, having a top speed of around 64.3 kph. (40 mph).

Slower and larger herbivores would have been the easiest meal for the large Giganotosaurus to catch. 


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