Amargasaurus

The genus Amargasaurus comprises a group of specimens that belong to the Saurischian dinosaurs, sauropods and dicreosaurids.

Although several fossil remains have been found, there is only one species, Amargasaurus cazaui, which lived during the Cretaceous Period, approximately 130 million years ago.

Its name comes from the Greek and means “reptile of Amarga”, since it was found in the La Amarga formation, which is located in the territory we know today as South America.

Like the Dicraeosaurus, the Amargasaurus was a dicreosaurid sauropod, which means that from its spine was born a spina bifida that ran along much of the neck and back, a characteristic of the group that is still studied today.

Will you join us in this adventure? Next, we are going to learn everything about the fascinating dinosaur Amargasaurus.

Taxonomy of the Amargasaurus

  • The Kingdom of Amargasaurus is Animalia
  • Amargasaurus belongs to the Filo or Chordata Division
  • This dinosaur is in a class called Sauropsida
  • Amargasaurus belongs to the superorder called Dinosauria
  • The order in which Amargasaurus is classified is Saurischia
  • The suborder of Amargasaurus is Sauropodomorpha
  • The infraorder this dinosaur belongs to is Sauropoda
  • This dinosaur’s superfamily is Diplodocus
  • This dinosaur belongs to the Family of Dicraeosauridae

As some fans of these prehistoric animals already know, this beautiful dinosaur called Amargasaurus, along with Dicraeosaurus and Brachytrachelopan (a huge sauropod that had the special quality of having a small neck), belong to a family called Dicraeosauridae.

There is a heated and frequent discussion about the comparison that arises between this dinosaur (Amargasaurus) and Dicraeosaurus, because they have notorious similarities, so it has been suggested that the former comes from the last beds of Tendaguru (Tanzania), due to the fact that the pre-sacral vertebrae have a very significant quality: a rare bifurcation of greater length and intensity.

When we mentally represent this dinosaur we must think of an animal that was actually of a large size and its growth was only due to its herbivorous type of food.
Its high spines had certain bifurcations, which were born from some of its vertebrae, and the most interesting thing is that among these we could find traces of skin, which had blood vessels that could fulfill the function of regulating its body temperature when necessary.

Besides, these spines were necessary to be able to get a mate, since at the time when all the males and females needed to mate, the crest present in the males was dyed in very bright colors in order to catch the attention of the females.

The life of Amargasaurus on planet Earth

This fascinating dinosaur lived in the territory we currently know as South America, estimated to be in the region of La Amarga, which gives it its name.

But in what period did this dinosaur inhabit our planet?

The Amargasaurus developed its existence during the geological period called Cretaceous, although if we want to be more precise we can determine that it lived during the beginning of this period, which takes us back to a time that took place approximately 130 million years ago.

The flora of the Cretaceous period provided this dinosaur with everything it needed to survive, and we are talking about flora since we are dealing with a herbivorous dinosaur, whose second essential element for survival was its robust structure, which acted as a defense against carnivorous feeding dinosaurs.

Who discovered this dinosaur?

In the first place, we must take into account and clarify that the name of Amargasaurus was “imposed” on it in 1991 by two famous paleontologists from the Republic of Argentina (South America):

Leonardo Salgado: He stands out for the accomplishment of a doctorate in one of the most prestigious and representative universities of his country, in the illustrious Universidad Nacional de la Plata. He is currently working as the main researcher at CONICET (National Council of Scientific and Technical Research), an entity that depends on one of the ministries of the Republic of Argentina.

Fernanda Ojeda Cruz: There is no public information available about this paleontologist and therefore it is not possible to highlight her work, however, we must treat her equally in everything that affects the discovery of Amargasaurus.

The remains of this dinosaur were found on the banks of a river with a peculiar name: “La Amarga”. This interesting river is located in the province called Neuquén, in the enigmatic Argentinean Patagonia.

However, the name of this river is also held by a small town located a few kilometers away from it. Besides, a famous geological formation was also named in the same way, all this contributed to the denomination of this specimen.

On the other hand, the specific epithet, “cazaui”, was placed in honor of the man who managed to discover the place itself, Luis B. Cazau, who developed his work as one of the best geologists of the YPF.

This place is actually located precisely in the lowest areas of the geological site mentioned above, the “La Amarga” Formation.

The Amargasaurus is known only by a skeleton, of which a meticulous replica was elaborated and is now available for exhibition at the Argentine Museum of Natural Sciences, which is called “Bernardino Rivadavia”.

The Amargasaurus Exhibition

The Bernardino Rivadavia Museum is the main, if not the most important, museum of Natural Sciences in the whole country of the Argentine Republic. This museum is also located in a quite typical place known as Parque Centenario, in the capital of Buenos Aires.

As last data, this museum has more than 200 years of existence, in the 2012 it was fulfilled its bicentennial.

This discovered skeleton contains the skull, the vertebrae belonging to the neck, as well as back and hip bones, without forgetting that a part of the tail was found.

We can also observe that the shoulder was found on the right side, as well as an upper extremity of the left lateral zone and a lower extremity of the same zone. Finally, a pelvic bone was found which turned out to be key for future investigations.

As we had already mentioned, a famous replica of this dinosaur is now on display for the general public at the Argentinean museum mentioned above. In fact, we found a relevant news item about it dated July 7th, 2015, which informs us about it and invites those interested to participate in this interesting exhibition.

Characteristics of Amargasaurus

This dinosaur was about 10 meters long, about 4 meters high and weighed about 8-9 tons, however, many scientists claim that it was actually quite small in size compared to the other sauropods.

On the other hand, we know that it was a quadruped whose skull was more elongated in comparison with other individuals, but that skull was low at one end, which was attached to a neck that had not very considerable dimensions, similar to the Dicraeosaurus, one of its closest relatives after all.

As you know, it had very high spines, in this it did surpass the other sauropods, since they were the highest spines that had been seen so far, which divided and later came out of certain vertebrae.

These famous and fearsome spines were born in the nape of the neck, then they passed through an area of the neck and were distributed even to the middle of the back of the Amargasaurus.

While some paleontologists claim that these tall spines held a kind of “candle”, this theory is rejected by one of the most controversial scientists known, the famous Gregory S. Paul, who rejected this claim in 2000, in a forceful way.

This researcher proposes the theory that in reality the spines were covered with a special fat that emitted this specimen, and even that they were surrounded by a specific muscle tissue, but even today it is not possible to affirm this fact with certainty.

Why was so much importance given to the fact that this scientist rejected the previously formulated theory about the high spines of Amargasaurus?

Gregory S. Paul is a great illustrator and writer in the field of Paleontology, mostly known for several of his works, but the world paid attention to him for his work called Predatory Dinosaurs of the World, which was published in 1998.

In addition, he is known for his harsh criticism of religion, to which he has devoted much of his efforts in recent years in order to overthrow it, an otherwise excessive goal.

Of American nationality (Washington DC), as we have already mentioned, he has developed his life and professional career in the fields of Paleontology, Sociology and even Theology, working independently for almost his entire career.

The most surprising quality of Amargasaurus

The most outstanding feature of the famous Amargasaurus skeleton is the group of high spines in the neck and back vertebrae.

The spines are the highest in the neck, an area where we can see that these spines are found in pairs, almost forming parallel lines.

As we see that the spines are getting closer to the hips we can see that their size decreases proportionally, so if we focus on the hip area, precisely on the last dorsal vertebrae, we will notice that they are much shorter compared to the neck spines.

If we take into account the theory of the candles that are formed thanks to the spines, we can reach certain conclusions, one of them is that one of the functions that these candles fulfilled was that of defense, besides which it is said that they also fulfilled functions that allowed communication between them, as well as regulating the temperature in critical moments.

But in reality we know very little, yet, about this dinosaur, so we cannot make totally true statements, something that usually happens in the scientific field.

The Amargasaurus had some nostrils whose characteristics seem to indicate that its diet was also based on the consumption of certain aquatic plants.
In addition to this, the teeth of this dinosaur had quite strange shapes that were rarely seen in other specimens, in fact they were shaped like what we now know as a pencil, that is, they were quite elongated, although this type of teeth can only be found in the front area of the jaw of the skeleton found.

Since its neck was not the longest, we can deduce that it fed on trees and vegetables that were within its reach, not too tall, nor do we claim that it fed on very short trees.

On the other hand, we can see that it had a special large-sized claw, which was very important when it tried to defend itself against other predators, and even this claw allowed this dinosaur to strike a strong and powerful blow against its opponents if necessary, a blow that alone was enough to defeat any other large animal, due to the power that it possessed.

As for its legs, we will focus first on the hind legs, which had the quality of being long, but not because they were weak legs, in fact they had a long but powerful muscle that gave them strength in key moments, even though speed was not their strong point.

Their tail was quite elongated, similar to the shape of a whip, and was used as such, since when they had a hand-to-hand fight or tried to defend themselves against other animals that harassed them, they chose to use their tail as one more weapon in their repertoire, and they delivered whips that caused serious injuries to their opponents.

It is for these reasons that we come to the conclusion that this animal was difficult to confront, above all because of the whip tail it possessed, counting also on the claws and its size, perhaps because of this its long existence within our planet, due to the fact that no other animal could face it easily.

Feeding and digestive functions of the Amargasaurus

As we have already mentioned, the famous Amargasaurus based its diet on the consumption of vegetables, in other words, it was an herbivore, just like its sauropod counterparts, of which we have already spoken a little in other articles.

On the other hand, we underline the shape and size of its neck, due to the great importance and influence of these structures in its diet.

Its neck was its main tool when looking for food, because if this animal had a short neck it was most likely to feed on vegetables or trees that were within its reach, that prevented it from reaching vegetables with much greater height. This anatomical structure largely determined its diet.

Another important point is the enormous size that this animal possessed, and it is obvious that in order to reach such dimensions it had to have ingested large quantities of vegetables, it is even presumed that this specimen did not manage to chew the leaves, since its stomach possessed small stones that help to perform such a function.

These stones were responsible for chewing or crushing the vegetable food that Amargasaurus ate; the name of these small stones was “gastrotrotrocytes”.

For that same reason we can observe that the teeth of this individual had the perfect form to tear and to pull up the vegetables (leaves) that were within its reach or that were within its possibilities, and already its stomach would be in charge to process it, to chew it and to digest it.

It is not known with total certainty but there is a high probability that this animal has fed mainly on conifers, however, it is also presumed that it included in its diet cycads, horsetails and many other similar plants or of the same family.

Conifers, from a totally ecological perspective, we can say that they are the main group of all gymnosperms groups that have existed. At a given moment in the history of our planet, these conifers were quite dominant in almost all communities around the globe.

On the other hand, cycads seem to be the only plants that have managed to survive to times that are really quite far away, it has come to be believed that they have achieved their evolution from another plant called “Seed fern”, which is actually an ancient plant that developed its existence during the late Paleozoic.

There is even an age that bears the name of these plants, the famous Age of Cycads, because they along with conifers were at the forefront of all vegetation in almost all the planet, distributed in a spectacular way.

As for their shape, their appearance is close to that of palms, but let us not be mistaken or confuse them because they have no relation whatsoever with the others.

Another fundamental aspect of Amargasaurus was the type of migrations it made in order to be able to feed itself properly, that is, in large quantities, these migrations basically consisted of eating everything they could in a certain place, they did it in a group, and then they traveled to another green place in order to continue feeding themselves properly.