The genus Herrerasaurus is a type of Saurischian Herrerasaurid dinosaur, which lived approximately 231 million years ago, in the Middle Triassic period, so it could be one of the first theropod dinosaurs due to its carnivorous and bipedal characteristics, with a skull vaguely reminiscent of a crocodile with a slightly short snout.

The meaning of Herrerasaurus is “Herrera’s lizard”, in honor of Victoriano Herrera who collected the first remains of this dinosaur in 1961 in the Ischiguaslato formation, in San Juan, Argentina (South America).

Taxonomy of the dinosaur

  • The specimen belongs to the Animalia kingdom.
  • This dinosaur corresponds to the phylum called Chordata.
  • It is part of the Sauropsida class.
  • The animal is located within the superorder Dinosauria.
  • It is a dinosaur whose order is called Saurischia.
  • It is located in the suborder Theropoda.
  • The family of which it is part is called Herrerasauridae.
  • It corresponds to the genus Herrerasaurus.
  • It belongs to the Species, which Reing called Herrerasaurus ischigualastensis.

Discovery of the Herrerasaurus

It was the great paleontologist Osvaldo Alfredo Reig who was in charge of reviewing the animal in 1963, although it was actually discovered in 1959 and only one species has been known about it, which has been called Herrerasaurus ischigualastensis.

As it has already happened with other dinosaurs, when it came to classifying the Herrerasaurus, some mistakes were made as there were scientists who classified it within the group of the basal theropods, whereas there was another group of researchers who said that it actually belonged to the group of the basal sauropodomorphs.

But there were also paleontologists who claimed that this dinosaur was actually a saurischian, and there were also those who directly classified it into the group of those considered as non-dinosaurs.

All these classification errors came to light when a bone structure was found in an excellent state of conservation and that for more in-ri it had all its elements, including the skull.

As an anecdote we can say that the fact of having found a complete skull in 1988 was a great help when carrying out various investigations and studies to get to know this dinosaur much better, thus clarifying many of the doubts about it.

Until that discovery, it was really complicated to define the position in which this species was found, as well as to know who its direct relatives were, due to the qualities and characteristics this dinosaur has, which may confuse any expert paleontologist.

This is one of the specimens that is considered one of the most ancient; at least among all the dinosaurs that have been known and found so far.

Characteristics of the Herrerasaurus

As we mentioned at the beginning, this dinosaur belongs to the Herrerasauridae family, which represents, to a great extent, the beginning of the era of dinosaurs.

The Herrerasaurus is a theropod dinosaur of quite discreet measurements, measuring between 3 and 6 meters long, that is, from its head to its tail, with a height of a little more than one meter, from the ground to its hips, and weighing between 200 and 350 kilos.

As a curiosity, we will tell you that his femur was only half a meter long

Although it must also be said that the remains of another Herrerasaurus were found with a much larger size, where only the bone structure of the skull measured a total of 56 cm in length. However, it should also be noted that these remains were initially considered to belong to a Frenguellisaurus.

But let’s go into a little more detail about what the Frenguellisaurus looked like:

Its neck

His neck was short, very robust and strong, which presented a great rigidity and power.

The vertebrae

Its vertebrae were of average size in terms of length, but very thick.

Perhaps the most striking thing is that it also had a set of spines that were square-shaped and thickened dorsally.

On the sacral bone of this mysterious creature we know that it is made up of a total of three vertebrae. In addition, we can affirm on the pectoral girdle, that this one exposes a strange element that is called scapular lamina, which was not very big although very robust.

Its tail

As for the tail, it is easy to deduce that it provided a great balance, since that is the function that these structures fulfill in almost all the species of our planet.

The tail could also become an extremely rigid and solid element, which indicates that this structure could have been used both for fighting and for increasing speed.

The extremities

If we were to compare it with other theropod carnivores we would notice that the herrerasaurus has short upper limbs with extremely long hands, there is the difference, in its hands.

These hands were formed by three fingers with enormous claws, where the third finger (as usual) is the longest. And then he would have two more, smaller, clawless fingers.

His hands together with his claws would serve him to hold on tightly to the prey.

The hands of the Herrerasaurus are very similar, if not almost the same, as those of the Abelisaurus.

However, in both cases these hands would be considered very primitive due to their morphology.

Their posterior extremities enjoyed a smaller size musculature in comparison with other carnivorous theropods; however, these muscles would have an enormous resistance.

Their feet in comparison to their legs have a great length. Not so, compared to other theropods.

But you may be wondering what this “three-legged” thing is all about. We’ll explain it to you right now.

The tridactyl comes from the fact that the metatarsal of the first toe is smaller in both length and thickness than the other three toes that make up his feet.

The Skull of the Herrerasaurus

The most striking thing about their skull is the length it had and above all its narrowness; a characteristic that has come to be compared with the Euparkeria, of the arcosaur family.

Another relevant feature of his skull is the long muzzle, which represents just over 50% of the total length.

As it happens in other species, the Herrerasaurus also has in its skull a series of depressions that will help it to reduce its weight. These holes are located in the area just behind where the eyeballs would be located.

It is also evident that there is an opening, which is located in the upper temporal area of the skull, and there was also a hole in the lower temporal area. All of them have a large size.

All these features come because it is a very “primitive” dinosaur, as we have already mentioned it is one of the oldest.

Besides this we can see that the area where the preorbital opening is located presents a great size; we can also see how the jawbone represents a wide extension and has a solid enough consistency. And all this set is linked to the bony element known as the nose.

The premaxillary also enjoys a very powerful and very solid consistency. It becomes so extensive that it even joins with the region occupied by the maxilla

All of this together tells us that the opening in the area of the nasal structure has a considerable thickness.

This unique animal also had a fairly flexible joint, especially in the area of the muzzle, precisely in the area where the teeth were located.

With all that has been described so far regarding its skull and jaw, what leads us to confirm is that once its prey was captured, it had no type of escape.

And with a structure provided with such a flexible character, what is obtained as a result is a powerful and lethal bite.

In addition, we can clearly see that the jaw area was composed of about 20 teeth with a serrated shape.

After the studies carried out, it is confirmed that the Herrerasaurus used the teeth in the anterior zone of the jaw region to capture and tear the prey, thanks to the position of the teeth there.

Special qualities and characteristics of Herrerasaurus

As we mentioned almost at the beginning of the post, there were some special qualities that only this dinosaur was able to present and that we are going to detail below.

One of them is the shape and design of the skull, especially let’s pay attention to the jaw, which had some mysterious holes, similar to the windows we know today.

Another unique quality in this dinosaur is that thanks to the disposition of its hind legs, already described above, they make it a great runner, being able to reach great speeds.

Another unique feature of this dinosaur is that it has a crest on the lateral surface of the jugal bone, which is a bone found in the jaw.

As we have already mentioned, its hands are extremely long; they measure a little more than half the length of the radius and humerus bones.

Habitat and food

As we have already mentioned, the Herrerasaurus was a carnivore, feeding on small and medium-sized animals, such as the dinosaur Pisanosaurus.

But taking into account that it lived during a time when dinosaurs were far from being the kings of the place; hence it is also believed that it would have fed on other types of non-dinosaur reptiles, such as rincosaurs and sinapsids.

In addition to the meat of its prey, it is known that it also ingested their bones.

And as an “insignificant” animal of the time, it would have been the prey of other giants of the time, like for example the saurosuchus, which when you see it can remind you of a crocodile.

By the way, it lived in the forests that covered the land of what is now South America.