About 98 million years ago, in the middle of the Cretaceous, northern Argentine Patagonia was an arid region with dune fields crossed by water courses with great seasonal variations, and with some patches of swamp forests. There they inhabited fish, amphibians, turtles, snakes and primitive mammals, pterosaurs and a great variety of dinosaurs. Among carnivorous dinosaurs, the largest is Giganotosaurus, one of the largest land predators of all time. Its name means “giant southern lizard” in Greek.
Giganotosaurus belongs to the family of carcharodontosaurs, which were the dominant apex predators during the Late Cretaceous, until they were replaced by tyrannosaurids in the northern hemisphere, and by the smaller abelisaurids in the southern hemisphere. Carcharodontosaurs are so named, which means shark-toothed lizards, from the shape of their teeth, serrated and laterally flattened.
The most complete remains of Giganotosaurus correspond to an individual 12 to 13 meters long, with a 1.5 to 180 meter skull, and weighing between 4 and 14 tons. This skeleton is exhibited at the Ernesto Bachmann Paleontological Museum, in Villa El Chocón, a town in the Argentine province of Neuquén, eighteen kilometers from the site where it was discovered.
Due to its large size, footprints that are somewhat more recent than the fossils have been attributed to Giganotosaurus: they are footprints of three long and thick fingers, with claws, 36 to 50 centimeters long, with a stride between one meter and one meter thirty .
Although Giganotosaurus’ size range matches that of other large theropods, such as Tyrannosaurus and Spinosaurus, its bones are more robust, so if it wasn’t the largest predatory dinosaur, it was possibly the largest.
Giganotosaurus is a bipedal dinosaur with a large skull and a short, stout neck that is less curved than other theropods. The arms are short, but not as short as those of the Tyrannosaurus; each hand has three fingers armed with sharp, curved claws with which it could hold onto its prey while biting it to death. The body, with a rather flattened back, is held in a horizontal position, and the long tail serves as a counterweight. The ribcage is oval, less wide than that of the Tyrannosaurus. The hind legs are large and muscular, larger than those of any other known theropod. The femur is longer than the tibia, which means that it was not very fast compared to other predatory dinosaurs; Even so, it is estimated that it reached 33 km/h.
Much information can be obtained from the composition of fossil bones. We already know that the ratios of radioactive isotopes of carbon, uranium, and other elements are used to determine the age of fossils. But much more can be known. For example, the ratios of oxygen isotopes to phosphate in fossil bones give us information about body temperature when the bones were formed. In warm-blooded animals, such as birds and mammals, these ratios are similar in all parts of the body, while in cold-blooded animals there are more variations. In the case of Giganotosaurus, the study of 84 samples from 13 different bones has revealed that the temperature difference between the vertebrae of the trunk and the tibia was less than five degrees Celsius, indicating that its metabolism was greater than that of reptiles. current cold-blooded, but less than that of birds and mammals. These results are similar to those of the Tyrannosaurus, and suggest an active life and rapid growth.
The Giganotosaurus brain is relatively small, 20% smaller than that of the Tyrannosaurus. The large size of the olfactory lobes stands out; the visual cortex is also developed, although not as much as that of the tyrannosaurus; In addition, its binocular vision is limited to an angle of between 20 and 35 degrees, compared to 50 for the Tyrannosaurus. All of this, coupled with its relatively slow running speed, suggests that it was adapted to hunting by ambush, or that it hunted slow prey, such as sauropods. Maybe he was a night hunter.
The cranial and jaw structure of Giganotosaurus differs in several respects from that of Tyrannosaurus. This is reflected in its functionality: Giganotosaurus’s bite force is less than half that of a Tyrannosaurus, but it is capable of closing its jaws more quickly. Giganotoraurus kills its prey with a succession of quick bites that cause deep wounds and profuse blood loss. If, as seems to be the case with its relative Mapusaurus, which we talked about in the Fossil Zoo episode dedicated to the argentinosaurus, Giganotosaurus lived and hunted in family groups, it could have hunted even the huge titanosaurs that inhabited the region, such as the aforementioned argentinosaurus. .
(Germán Fernández, 09/27/2022)
CONSTRUCTION OF GERMAN FERNÁNDEZ:
reticular infiltrate
Reticular Infiltrator is the first novel in the trilogy The Saga of the Borelians. Do you want to see how it starts? Here you can read the first two chapters.
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