• Gorgosaurus – Resumenea

What is a Gorgosaurus?

Gorgosaurus libratus was a dinosaur that lived in the last phase of the Cretaceous in what is now known as North America. Its length was about 8 meters and it could weigh between 2 and 3 tons.. It was a close relative of Tyrannosaurus rex.

It was characterized by having two horn-shaped protuberances over its eyes. In the same way as tyrannosaurs, it had two small arms that had two fingers. It was a ferocious carnivore with large, muscular and powerful legs on which it moved. It had a powerful bite, with 60 sharp teeth with which it could cut flesh and break bones.

Gorgosaurus discovery

The first skeleton of Gorgosaurus libratus was found in 1913 by Charles H. Sternberg. It was in the Dinosaur Park Formation in Alberta. You can currently see this specimen at the Canadian Museum of Nature in Ottawa.

The holotype specimen was a practically complete skeleton that was associated with a skull. At that time, the researchers at this museum had actively worked on the banks of the Red Deer River in Alberta, Canada.

As a result, they had found hundreds of fossil specimens, including complete skulls of Gorgosaurus libratus, which were related to three skeletons.

The first formal description of this species was made in 1923 by Matthew and Brown.

These researchers also described a fifth specimen. It was a different skeleton than Charles H. Stenberg in 1917. Everything indicated that it was a juvenile specimen. It was smaller, its skull was low and light and its limbs were proportionally elongated. It was named Gorgosaurus sternbergi. Although currently the consensus is that it will be an individual going through puberty.

The Dinosaur Park Formation has been the source of other specimens of Gorgosaurus libratus, which today can be found in Canada and the United States. Thanks to this, it is the species of tyrannosaur that is best represented in the fossil record.

Joseph Leidy described two premaxillary teeth of tyrannosaurs in 1856, which had been found in Montana. They were large and robust, and he assigned them to Deinodon. Specialists Brown and Matthew said in 1922 that they were similar to those of Gorgosaurus. But because they could not be compared with bone remains of Deinodon, they refused to relate these genera. Although they had similarities, it was not possible to say exactly which animal they corresponded to.

On the other hand, several skeletons found in the Judith River formation in Montana are tyrannosaurids with great possibilities of being Gorgosaurus. Although that has yet to be determined by the experts.

What does Gorgosaurus mean?

The name Gorgosaurus libratus comes from the Greek gorgos what does it mean terrible. This term also has to do with The Gorgons who were three monstrous sisters who offered terrible predictions. It is completed with saurus what is lizard.

So his name translates as terrible lizard either gorgon long. The epithet libratus is the participle of the Latin verb I will free which means to balance.

The Tyrannosauroidea group

Gorgosaurus was a specimen of the Tyrannosauriodea, which was a super family of bipedal carnivores and coelurosaurids. The first species existed in the Jurassic period 163 million years ago. But then it was specimens like Dilong or Guanlong that were small.

As they evolved, they grew, as was the case with Tarbosaurus and of course Tyrannosaurus rex itself. Its remains have been discovered in North America, South America, Asia, Australia and Europe.

The first tyrannosaurids had light, flat and long skulls, so they resembled Coelurosaurus. Later species had firmer skulls with large teeth and iron jaws.

They also had S-shaped necks and long tails. Their legs were strong, long and muscular, with which they could run quickly. But the arms of these specimens were short and had only two fingers.

They lived at the end of the Cretaceous and were almost always the largest predators in their respective ecosystems. Its cranial anatomy has been well documented. The skulls of Tyrannosaurus, Tarbosaurus and Dapletosaurus had a length ranging from 1 meter to 1.5 meters for T. rex.

They balanced their huge bodies on their midsection legs with the help of their muscular tails. One of the premises that predominated in this group was that their diet was scavengers. But recent research showed that they were capable of deploying high speeds in the short term to follow their prey. They could be scavengers depending on the opportunity.

Comparing Gorgosaurus and Albertosaurus

The Gorgosaurus and Albertosaurus were two tyrannosaurid, theropod and carnivorous dinosaurs. And knowing that they had a lot in common, it is natural that they are often compared to each other.

They had marked similarities in their skulls and skeleton, as well as the fact that the two genera lived at the same time and in the same territory. So it is not an exaggeration to assume that they met and even clashed.

Studies have determined that Gorgosaurus had slightly longer legs than Albertosaurus. The length of the jaw, shape and size of the skull were also different.

Albertosaurus boasted a slightly lighter and smaller skull. It had a short, thick snout, which may have allowed it to bite harder.

By measuring its bones, specialists concluded that Gorgosaurus also had a slightly longer stride. Comparison of different specimens also indicates that it was a little more agile and faster.

In short, Gorgosaurus stood out for being smaller and more agile in comparison, as well as being faster. On the other hand, the Albertosaurus turned out to be a little larger and it is possible that it had a stronger bite.

However, both species had similar characteristics. So it is not easy to declare one specimen the winner over the other.

Characteristics of the Gorgosaurus

The various studies on Gorgosaurus remains have allowed specialists to learn a lot from them. That is why they have synthesized the following particularities.

Classification

The Gorgosaurus belongs to the Albertosaurinae theropods, and is located in the Tyrannosauridae family. All the genera of tyrannosaurs that have species such as Dasapletosaurus, Tarbosaurus and Tyrannosaurus, also make up the Tyrannosaurinae. When compared to the latter, albertosaurines were distinguished by being thinner and more agile.

Due to the similarity between Gorgosaurus libratos and Albertosaurus sarcophagus, specialists made the decision to combine them into the same genus. According to the nomenclature rules, the name Albertosaurus was used since it was the first to be named.

Barnum Brown and William Diller Matthew questioned the distinction of the two species in 1922. But in 1970, Dale Russell formally reassigned G. libratus to Albertosaurus. However, other specialists keep them separate.

One of these was Phil Currie, a Canadian paleontologist, who stated that there are organic differences between Albertosaurus and Gorgosaurus, as between Tyrannosaurus and Daspletosaurus.

During the 20th century, various dinosaurs were mistakenly assigned to Gorgosaurus. One of these was initially called G. Lancensis, whose description was made in 1946 by Charles Whitney Gilmore. In 1988 the North American paleontologist renamed it Nanotyrannus. Other specialists suggested that it was a juvenile specimen of T. rex.

On the other hand, the skeletons of Gorgosaurus novojiovi and Gorgosaurus lancinator were found in Mongolia. But they were later assigned as juvenile versions of Tarbosaurus bataar. The smallest was named Maleevosaurus novjilovi in 1992.

When he lived

It lived in North America in the Cretaceous period between 76 and 65 million years BC. It was one of the most powerful predators in the region. However, it coexisted with other tyrannosaurs, such as Albertosaurus, with which it is possible that it had a marked rivalry.

Habitat

At the time of Gorgosaurus, what is now North America was divided by a bight, which was a Western Interior Seaway.

Its habitat had a subtropical climate, which alternated with dry periods. When this happened there was a shortage of food, which was the cause of the mass extinction of large herds of dinosaurs.

The vegetation consisted of superior and tall plants such as conifers. There were also ferns, angiosperms and tree ferns that were abundant in the low areas.

This was an abundant food source for ceratopsids, and groups such as saurolophines, and hadrosaurs.

Development

It is estimated that Gorgosaurus spent the first half of its life in the juvenile stage, developing only 70% of its adult size. Then over the next 4 years he built up to his maximum size, gaining up to 110 Kg per year.

That was a growth rate similar to that of Albertosaurus. But it was slower than what dinosaurs like Tyrannosaurus and Daspletosaurus experienced.

According to a 2012 scientific article, Gorgosaurus exerted a bite force of 42 thousand Newtons. To understand a little better, it is enough to compare it with the lion’s bite force, which is 3380 Newton per square centimeter.

However, scientists say they may not have broken bones as frequently, not like Tyrannosaurus rex routinely did.

Most likely, they focused more on tearing the flesh of a prey. Its narrower snout was indicative of a weaker bite.

Diet

In this matter, the idea of niche division is applied, which is valid in both carnivores and herbivores. This would explain that Gorgosaurus hunted different prey than its larger, stronger cousins hunted.

One of the specimens with which it lived was the Daspletosaurus, which could weigh up to 1 ton more than the Gorgosaurus. It is possible that it hunted large, horned dinosaurs.

On the other hand, specimens such as Gorgosaurus and Albertosaurus preyed on small animals such as pachycephalosaurus and hadrosaurus.

Lifestyle

It is known that Gorgosaurus shared territory with Daspletosaurus. While the former inhabited the northern part, Daspletosaurus remained more in the south of what is now Alberta.

According to the fossils studied, it is believed that Gorgosaurus lived in herds and even took care of each other. They were feared hunters, who preyed on ceratosaurs.

Skull

The largest Gorgosaurus skull ever found was 99 centimeters long.. This made it relatively large, something common in tyrannosaurids. It had large openings in the skull and chambers within the skull bone that reduced its weight.

The snout of the Gorgosaurus was…