Giganotosaurus: Was this the apex predator of its time?

Gigantosaurus in Jurassic World Dominion

Was Giganotosaurus the biggest carnivore that the World has ever seen? And how would it compare to a T. rex?

The main dinosaur antagonist in Jurassic World Dominion, Giganotosaurus, was marketed throughout the movie as the biggest carnivore that the World has ever seen. A claim that was given strength by this franchise's main paleontologist, and fan favourite, Dr. Alan Grant.

Giganotosaurus was first featured in Jurassic World Dominion's prologue, a short film released in theatres as an IMAX-exclusive before the showing of Fast 9. In this prologue, we travel back to the late cretaceous of North America, 66 million years ago, where we see several dinosaurs in their natural environment, like Dreadnoughtus, Nasutoceratops, and Oviraptor, and where we are first introduced to the giant azhdarchid Quetzalcoatlus.

At the end of this prehistoric journey, we witness a fight between a Giganotosaurus and a feathered T. rex. The Giganotosaurus manages to beat the tyrant lizard king, leaving it to die at the base of a river. We then see a mosquito biting the fallen T. rex and are brought back to our World, where the T. rex from the original Jurassic Park is being chased by a helicopter after escaping from Lockwood Manor. Giving us a hint that this animal was cloned from the DNA extracted by the same mosquito that bit the fallen T. rex, 66 million years ago.

There are many issues with this short film but the main one is that Giganotosaurus and T. rex would have never met. Giganotosaurus, whose name means giant southern lizard, lived during the Late Cretaceous, approximately 99,6 to 97 million years ago, while Tyrannosaurus rex lived from 68 to 66 million years ago. This means both animals were separated by more than 30 million years.

If time wasn't enough, both animals lived on opposite sides of the globe. While T. rex lived in North America, Giganotosaurus fossils have been discovered in the Candeleros Formation of Patagonia, in Argentina. Two continents that, at the time, were separated by a large ocean, meaning that even if both animals had lived at the same time, the likelihood of them ever meeting would be very low.

Giganotosaurus vs. T. rex

Giganotosaurus vs. T. rex in Jurassic World Dominion

Although the first T. rex fossils were found in 1874 by Arthur Lakes near Golden, Colorado, we would have to wait 30 more years for Henry Fairfield Osborn, president of the American Museum of Natural History, to in 1905 give this animal the name that would catapult it to stardom.

But, how big was a T. rex? One of the largest and the most complete specimens was Sue (FMNH PR2081), which can currently be seen at the Field Museum of Natural History, in Chicago. Sue measures about 12,4 meters in length (40.7 ft), 3,96 meters (13 ft) in height, and has been estimated to have a mass of about 8,4 metric tons (9.3 short tons).

However, the title of biggest T. rex ever found belongs to a specimen nicknamed Scotty (RSM P2523.8), located at the Royal Saskatchewan Museum. Scotty is reported to measure about 13 meters (43 ft) in length, with an estimated mass of 8,87 metric tons (9.78 short tons).

Discovered by Rubén D. Carolini in 1993, Giganotosaurus was one of the largest known terrestrial carnivores, however, its exact size has been hard to determine due to the fact that paleontologists have yet to find a complete specimen.

The skeleton of Giganotosaurus holotype specimen (MUCPv-Ch1) was about 70% complete and included the skull, pelvis, leg bones, and most of the backbone. A holotype is a single physical example of an organism, living or extinct, known to have been used when the species was first formally described.

Scientists estimate that MUCPv-Ch1 measured about 12,5 meters (41 ft) in length, with a body mass of 6,6 metric tons (7.3 short tons). However, a second specimen (MUCPv-95) has also been discovered. Although this specimen's remains are more fragmentary than the holotype's, it is estimated that this individual was about 13,2 meters (43.3 ft) long, with a mass between 7 and 8 metric tons (7.7 and 8.8 short tons).

Giganotosaurus also had one of the longest known skulls for a theropod dinosaur, with the holotype's skull estimated at 1,80 meters (5.8 ft) and the second specimen's estimated at 1,95 meters (6.3 ft). The largest known T. rex skull measures about 1,52 meters (5 ft) in length.

This means that Giganotosaurus would surpass T. rex in length by less than half a meter, however T. rex would've been a more massive animal, weighing almost one metric ton more than Giganotosaurus.

In fact, Spinosaurus would probably be a better contender for the title of biggest carnivore the World has ever seen, with a skull 1,75 meters (6 ft) long, a length of 14 meters (46 ft), and an estimated mass of 7,4 metric tons (8.2 short tons).

However, with Spinosaurus evolving to adapt to a semiaquatic lifestyle, its jaws were better equipped to hunt fish rather than fight off large theropods, dropping Jurassic Park III's main star to last place.

But when it comes to T. rex and Giganotosaurus, their size would put both animals as the apex predators of their own ecosystems.

As for who would win in a fight? My money is on our not-so-friendly neighbourhood tyrant lizard king.