The flexible lizard

  • Name: Camptosaurus
  • Diet: Herbivore
  • Weight: 2 tons
  • Period: Late Jurassic
  • Found In: USA

Camptosaurus was a genus of dinosaurs that would have inhabited our Earth during what is now known as the Jurassic Period, approximately 150 million years ago.

It has been classified among the group of the ornistich dinosaurs.

This genre would have had a corpulent general appearance, although what really stood out was the incredible flexibility it possessed.

In fact, its name, which comes from Greek, refers to its great flexibility, since translated into our language the meaning of its name is that of flexible lizard.

In terms of dimensions, they would have been those of a medium-sized dinosaur.

It was about 7-8 meters long, 2 meters high and would have been about 2 tonnes in weight.

This is just a summary of all the information we have about Camptosaurus – read on if you want to know more about this amazing Jurassic herbivorous dinosaur!

Camptosaurus taxonomy

  • Camptosaurus belonged to the Animalia kingdom.
  • The edge of this extinct animal is Chordata.
  • This specimen was classified in the Sauropsida class.
  • He obviously belonged to the superorder Dinosauria.
  • The order in which we found him is Ornithischia.
  • He was classified in the Ornithopoda infra-order.
  • The superfamily he belonged to is Camptosauroidea.
  • We found it classified in the Camptosauroidae family.
  • The genre we are referring to is Camptosaurus.

Currently, the taxonomy of this dinosaur states that the genus Camptosaurus is represented by a single species called C. dispar.

However, this could change if new fossil remains were found from the same family but with enough evidence to determine that it is a new species.

Therefore, from this platform, we will do our best to keep the information regarding the biological taxonomy of Camptosaurus updated.

Basic information about the Camptosaurus

The Camptosaurus was a medium-sized dinosaur, although there are not really many samples discovered on this dinosaur, however, this is the information that paleontologists have determined.

  • How long was it? Approximately 6 meters in length.
  • What was his height? The height of Camptosaurus was not exaggerated either, it is estimated that it reached about 2 meters.
  • What was his weight? Its weight was approximately 2 tons.
  • When did he live? This animal was on Earth 152 million years ago until 145 million years ago (Late Jurassic).

As you can see throughout this article, Camptosaurus had almost all the general characteristics of ornitischia.

Although it also had some characteristics that differentiated it from other ornitischic dinosaurs.

One could say that the Camptosaurus was corpulent. His hind limbs were very robust and they had large feet and four toes.

However, their arms or front legs were very small and had three fingers on each. The middle finger was a large claw that they used to defend themselves from predators.

The other two fingers of his hands, on the other hand, did not have such specific functionality or importance, as they were actually small hooves.

Although we have already observed the main characteristics of Camptosaurus in adulthood, it must be said that specimens have also been found that were smaller and barely six meters long and weighed only 800 kilograms.

We should also mention that although the ornitischia had a rectangular skull, this is not the case of Camptosaurus.

These dinosaurs have rather a triangular shaped skull, with a characteristic very pointed snout.

His head was very long and wide. It also had a horny beak and its tongue would be very similar to that of the giraffes.

Another rather curious thing about the characteristics of Camptosaurus is that its tendons evolved in a strange way.

In early ages, they had collagen tendons, like all living things, but as time went on, their tendons became bone rods.

This is something that allowed him to stand up on his hind legs and place his back straight, adopting a bipedal position.

Another aspect to which we must refer is the speed that Camptosaurus could reach.

Taking other iguanodonts as an example, it is thought that this dinosaur could have reached speeds of 25 kilometers per hour.


Certainly, a great speed compared to many other dinosaurs, but we must also say that it falls short of others like the Velociraptor.

These speeds would be reached thanks to the curved bones that point forward allowing this dinosaur to reach these speeds using its tail to achieve balance.

The bad thing about Camptosaurus is that he had nothing to defend himself against his enemies. Despite this, he had another virtue, he was a flexible dinosaur and could put his head at different heights.

The life of the Camptosaurus on planet earth

Many, many, many years ago these quadrupeds inhabited the earth. So many years have passed since then, so many rains have fallen that one cannot even imagine it.

No doubt it is difficult to imagine so many years, since not even the entire existence of the human race (homo sapiens sapiens) is 200,000 years old.

How many years are we talking about? A few million? Definitely not. Definitely not. We’re talking about much more than a few million, we’re talking about 152 million years. Specifically, it belongs to the Late Jurassic, also called the Upper Jurassic.

They disappeared from the earth in the Lower Cretaceous about 152 to 145 million years ago.

The area where this dinosaur is believed to have lived is the vast territory we know today as North America and it is quite possible that it also inhabited Europe.

It goes without saying that obviously North America and Europe did not exist because the geological distribution was completely different.

Did you know that Camptosaurus had numerous enemies? No doubt this dinosaur was not a predator but rather the hunted animal.

It is assumed that this extinct animal coexisted with several dinosaurs that would have attacked poor Camptosaurus to eat him.

Among its possible enemies are the Allosaurus, Ceratosaurus and the Torvosaurus, which are theropod dinosaurs.

However, we must mention that we do not know for sure if he really lived with Allosaurus, because in the deep layers of the Morrison Formation no material that belonged to the Allosaurus has yet been found.

The only confirmed theropod that was with Camptosaurus is Coelurus. However, this theropod did not really pose any threat to an adult Camptosaurus.

The feeding of the Camptosaurus

We can get some idea of the Camptosaurus’ diet if we look at the remains found of this dinosaur, thanks to which it has been concluded that this huge reptile was a hervíbore animal.

Perhaps the dinosaurs belonging to this genus were not the largest, nor were they the most defensive, but they did have another advantage over the others in terms of food.

The Camptosaurus had hard, saw-shaped teeth, which allowed them to eat harder vegetation. However, his teeth were becoming smooth after crushing the vegetation with such force.


Even so, the most interesting thing about their diet is the position they took to eat vegetation.

As we have seen before, the Camptosaurus had very robust hind legs that allowed them to stand upright. This favoured the dinosaur in this article, as it could reach vegetations at different heights.

In order not to fall over while standing on two legs, he used his tail to support himself and not to lose his balance, so that he could stay up as long as he needed.

In addition to his saw-shaped teeth and the possibility of being able to put his head at different heights, he also had a strong beak with which he could pull up the vegetation to take it to his mouth.

The discovery of the Camptosaurus

Many fossils of this dinosaur have been found, so we can deduce that it was a common dinosaur during the late Jurassic period.

Camptosaurus was discovered in 1879 by William Harlow Reed in Albany County, Wyoming. But that same year, all the credit went to the very famous Professor Othniel Charles Marsh.

Marsh traveled that same year to investigate the finding, describe it and even named it Captonotus (flexible back). This name was given to the dinosaur thinking of the enormous flexibility it possesses.

About six years later, in 1985, he himself changed the name to Camptosaurus, since the first name given to it by this quadruped (or rather a biped) belongs to a species of cricket.

The first specimen (holotype YPM 1877) found by its collectors (specifically William Harlow Reed) was called the C.dispar species.

This first specimen was discovered specifically at mine 13, near the Como Bluff area of Wyoming City (which is in the Morrison Formation).

The YMP 1877 holotype was a partial skeleton.

The second was called C. amplus (holotype YPM 1879). He was found by the Arthur Lakes collector at quarry 1A. It was later learned that this holotype really belonged to an Allosaurus and that Marsh had misclassified it.

The YMP 1879 holotype was of an Allosaurus foot that was mistaken for a Camptosaurus foot.

During the 1880s and 1890s, samples continued to appear at mine 13, so many that two more species were eventually discovered, C. medius and C. nanus, whose classification was almost based on the size of the fossil remains.

Did you know that finally, all the species of Camptosaurus became one? It is Camptosaurus dispar.

In 1909, two new species named after Charles W. Gilmore appeared: C. browni and C. depressus.

Peter Galton and HP Powell, in 1980, completely redefined the different species of Camptosaurus. Both C. nanus, C. medius and C. browni are considered as a Camptosauris dispar.

This is because the different species described are actually Camptosaurus disparus at different ages.

There was another confusion with the YPM 1887 holotype which was classified in 1886 as C. amplius by paleontologist Marsh, which was later clarified by Gilmore, who stated that like all holotypes, it was a Camptosaurus disparus.

Gilmore used the YMP 1887 (a skull) to define the characteristics of a camptosaurus skull. In 2007, Brill and Carpenter demonstrated that it was really neither a C.dispar nor a C.amplius, but a separate species called Thelophytalia kem.

But did you know that many more confusions continued to arise around Camptosaurus? Next, we will explain how the same were given in different investigations.

Simultaneously, while Marsh was investigating and describing Camptosaurus, numerous dinosaur remains were found in Europe, which they also called Camptosaurus.

Some of the species would be: C.inkeyi, C.hoggi, C.leedsi, C.valdensis, C.prestwichi… All of them are supposedly Camptosaurus species that have been discarded over time.

  • C. inyeki is now considered to be a rhabdodontide.
  • C. valdensis is currently classified as a dubious driosaurid (it cannot be known exactly because the only thing that exists is the NHMUK R167 holotype, which is a very poorly preserved femur).
  • C. leedsi came to be considered a Driosaurid and now belongs to a new genus called Callovasaurus.
  • C. hoggi was originally an Iguanodon hoggi according to Richard Owen in 1874. In 2002 he was moved to the genus Camptosaurus by Norman. His current name is Owenodon.
  • C. depressus was classified by Gilmore in 1909. In 2008, Carpenter and Wilson classified it in the genus Planicoxa, now called P. depressa. In 2010 Andrew McDonald proved it wrong and moved on to the new Osmakasaurus genre.
  • C. aphanoeceles was classified in 2008 by Carpentier and Wilson, differentiating it from C. dispar by its jaw, spine and ischium. Finally, McDonald showed that it was more related to the genus Uteodon.

Misclassification in the genus Camptosaurus

The erroneous classifications of the different dinosaurs, not only with the Camptosaurus, but in general, are due to the ignorance and the margin of error that exists in all interpretations of the paleontological tests.

Obviously, the dinosaurs left no writing, no drawings or clues other than their fossil remains, and since they are not contemporaries of human beings, no one was able to investigate the life of these extinct animals in the present.

These remains are being discovered relatively recently and also incomplete fossils are found or that cannot be compared with similar anatomical structures, so there may be confusion.

This is the problem of Camptosaurus, it has many characteristics similar to different genres of dinosaurs, that is why it is not easily distinguished and requires a great deal of work for a proper classification and description.

In fact, one anecdote that should not be overlooked is that the best preserved skeleton of a Camptosaurus was initially an Iguanodon prestiwichii (classified within the genus Cumnoria by paleontologist Seeley in 1888).

It was not until 1889 that Lydekker moved it to Camptosaurus and it is currently the best preserved skeleton of the genus. And this is how the skeleton of the non-camptosaurus was finally the best preserved skeleton of Camptosaurus.