What’s the first Dinosaur that comes into your head when someone says, “What’s the biggest carnivorous dinosaur?” Was it Tyrannosaurus Rex, or perhaps even Spinosaurus? Well, prepare to meet your new favourite carnivorous dinosaur that was bigger, scarier, and more ferocious than both – that dinosaur was called Giganotosaurus.

Pronounced “Gee-gah-no-toe-sore-us” Giganotosaurus in Greek means `giant southern lizard.” There is quite a lot of misinterpretation around the name, so it is important to understand that Giganotosaurus does not mean “Gigantic Lizard”. We think this confusion around the name may stem from other animals and Dinosaurs that are referred to as “Giganto” such as the Gigantoraptor, which is best described as a gigantic Oviraptorosaurian dinosaur.


Ryanz720, Public domain, via Wikimedia Commons


Another interesting fact about Giganotosaurus as this Dinosaur is not classed as “tyrannosaur”.

Giganotosaurus was classed as a theropod like other similar looking Dinosaurs, but more specifically Giganotosaurus was known as a “Carcharodontosaurus,” which includes some of the longest and heaviest known carnivorous dinosaurs ever to be discovered.


Quick Giganotosaurus Facts

Name Giganotosaurus
First Found: Argentina by Rubén D. Carolini
When it lived: Late Cretaceous period, 98-97 million years ago
Weight: 4.2 – 13.8 tons
Length & Height Up to 12 to 13 m (39 to 43 ft in length)
Diet: Carnivore

what did giganotosaurus eat?

It is believed that Giganotosaurus would have fed on juvenile sauropod dinosaurs, such as Argentinosaurus and may have lived and hunted in packs. The evidence to this theory was put forward in 2006 by Rodolfo Coria and Leonardo Salgado after a group of closely related Mapusaurus were discovered, which include several different age groups of dinosaur, suggesting that these apex predators would have lived and hunted together in groups.

When you think about it, it does make sense. An animal as big as Giganotosaurus would have been able to hunt some of the largest sauropods ever to exist. This task would have been a lot easier working as a team to take down some of the biggest sauropods.

Of course, we’ll never know for sure if Giganotosaurus would have hunted in this way, but with every new discovery will hopefully shed new light on how this dinosaur lived.

How big was Giganotosaurus?

Though palaeontologists believe that Giganotosaurus was one of the largest theropods ever, there is still a level of caution around the true size of Giganotosaurus, mainly due to the lack of complete specimens uncovered. However, it is strongly believed based on incomplete fossils discovered of Giganotosaurus that it could have been larger than the famous Tyrannosaurus rex, but until palaeontologists discover a more complete specimen, the jury is still out on this one…for now.


User:Slate Weasel, Public domain, via Wikimedia Commons

So, with that said, let’s discuss the size metrics we do know about Giganotosaurus. As already mentioned, the exact size of Giganotosaurus is a little tricky due to a lack of complete fossil remains. So, based on what we know Giganotosaurus size would be between 12 to 13 m (39 to 43 ft in length). Giganotosaurus’ skull is between 1.53 to 1.80 m (5.0 to 5.9 ft) in length. The metric that seems to be the broadest is the weight of Giganotosaurus which is thought to be between 4.2 to 13.8 tonnes.

Even though Giganotosaurus was bigger than Tyrannosaurus rex its brain unfortunately was not any bigger, and in fact scientists believe that it was a lot smaller. Some palaeontologists have made comparisons to the size and shape of its brain to that of a banana. This is because of the shape of the Giganotosaurus skull it would possibly mean that its brain would have been slightly elongated.

What did Giganotosaurus look like?

In terms of looks Giganotosaurus wasn’t too dissimilar from Tyrannosaurus rex. It had a very large head, walked on two hind legs, and had two small arms, with the only real noticeable difference was its size.

Another key difference was the pure speed that Giganotosaurus could reach. I’m sure you can remember the scene in Jurassic Park where Tyrannosaurus Rex chases after a little Jeep. Well, it is believed that Giganotosaurus could reach a speed of 20 mph when running flat out, (for a short period of time) so it’s prey would have had to have been pretty quick to escape this apex predator.


Casliber, Public domain, via Wikimedia Commons

Based on reconstructions of this Dinosaur is believed that Giganotosaurus skin would have more than likely been camouflaged helping it to blend into its surroundings. Well, the best it could considering its size.

Who discovered Giganotosaurus?

If you’re a keen fossil hunter yourself then this next section could inspire you, as Giganotosaurus was discovered by an amateur fossil hunter.

In 1993, Rubén D. Carolini hit the equivalent of the fossil hunter’s jackpot! Rubén D. Carolini was digging around in the dirt in Patagonia when he discovered the tibia (lower leg bone) of what would be later named Giganotosaurus. As more time was spent on the site more bones were discovered including its skull, hips, and most of the back and leg bones. Unfortunately, it was not a complete skeleton, totalling around 70 percent.

The announcement to the scientific world was then announced by palaeontologists Rodolfo Coria and Leonardo Salgado in 1994. Both Rodolfo Coria and Leonardo Salgado both went one to study Giganotosaurus extensively, and proposed many theories on how Giganotosaurus lived.

This was given its full name “Giganotosaurus carolinii” name in 1995 to honour Rubén D. Carolini’s incredible discovery.

When did Giganotosaurus live?

Giganotosaurus lived approximately 98 to 97 million years ago in the Late Cretaceous period.

The part of the world it would have lived in the southern hemisphere, with its habitat would have been in and around the plains and woodlands of South America which is now called Argentina.



Durbed, CC BY-SA 3.0, via Wikimedia Commons

Similar dinosaurs to Giganotosaurus

As we’ve already discussed, Giganotosaurus was known as a “Carcharodontosaurus,” which includes some of the best-known carnivorous dinosaurs ever to be discovered, so similar dinosaurs include.

Tyrannosaurus rex

The name Tyrannosaurus originates from Greek words and means “King of the tyrant lizards”. When broken down it means “Tyrant” and “Lizard”, the Rex in Latin means “King”. It’s often referred to as “T Rex” for short.

The Tyrannosaurus rex lived on earth 68-66 million years ago during the Cretaceous period. This period was after the Triassic and Jurassic periods.
It was one of the last non-avian dinosaurs to exist before the extinction event which wiped out the dinosaurs. You can read more about Tyrannosaurus Rex by clicking here.

A lot of comparisons are made between Tyrannosaurus rex and Giganotosaurus. This level of comparison can cause some confusion as a lot of people then assume that these two dinosaurs lived and terrorised the earth at the same time. The fact of the matter is that these two dinosaurs lived 30 million years apart, with Giganotosaurus roaming the planet before so called “King of the Dinosaurs” the Tyrannosaurus rex, roamed the plains of North America.

Tyrannosaurus rex

DataBase Center for Life Science (DBCLS), CC BY 4.0, via Wikimedia Commons


Spinosaurus was from a family of dinosaurs called Spinosaurids. This unusual family of dinosaurs all had tall spines or sails along their backs and included the terrifying Spinosaurus.

Spinosaurus was massive! Scientists believe that it was between 10-18 meters in length and weighed up to nearly 20 tonnes. Even compared to other huge dinosaurs such as Giganotosaurus and Carcharodontosaurus, Spinosaurus was a terrifying dinosaur.

Scientists who were studying a near complete Spinosaurus skeleton from 2014-2018 released a research paper confirming the earlier theories of how big Spinosaurus could get too and concluded that Spinosaurus could reach lengths of up to 16 meters.

You can read more about Spinosaurus by clicking here.


DataBase Center for Life Science (DBCLS), CC BY 4.0, via Wikimedia Commons

Summary of Giganotosaurus

  • The very first Giganotosaurus was discovered in 1993 by Rubén D. Carolini, a then amateur fossil hunter.
  • The discovery was made in Argentina and the spiecies was named in 1995 Giganotosaurus carolinii, in honour of Rubén.
  • The holotype skeleton is kept at Ernesto Bachmann Paleontological Museum in Vella El Chacon, Argentina.
  • Giganotosaurus was a theropod dinosaur
  • It was a carnivore and fed on juvenile sauropod dinosaurs.
  • Giganotosaurus weighed 4-2 to 13.8 tons (4,200 – 13,800kg) and was up to 13 meters long (43 ft).
  • Giganotosaurus lived during the Late Cretaceous period 98 – 97 million years ago.

Last Updated on 15/07/2022 by