What is a Camptosaurus?
Camptosaurus was an ornithischian dinosaur from the Iguanodontia group that lived during the Late Jurassic in North America and Europe. It is known to have existed from 160 to 145 million years ago. It is believed that it was up to 7 meters long and weighed around 2000 kilos..
It was known from an incomplete skeleton found in the Morrison Formation in Wyoming, in the United States. It is believed that it was a grazing animal that fed on low plants and bushes close to the ground.
Specimens of Camptosaurus have also been found in Europe, which shows that the species existed throughout the world. Othniel Charles Marsh originally named him Camptonotusin the original description of 1879.
But the name was changed to Camptosaurus in 1885 as the previous name was already used to refer to long-horned crickets.
Adult Camptosaurus is thought to have been 2.5 meters tall, so it was not a very large dinosaur. Its strong skeleton had enormous hind legs that ended in a wide foot with four toes.
They moved on two legs and sometimes on four. The fossils found show that they have coexisted with herds of Stegosaurus. This could have been due to the fact that they did not compete for food since they lived in a grazing succession.
This means that they fed using all the resources of a biotope without having to compete for food.
Camptosaurus discovery
The first discovery of the Camptosaurus was thanks to William Harlow Reed, in Albany County, which belongs to the state of Wyoming, United States. The discovery was that of a euornithopod that Othniel Charles Marsh described and named that same year.
In 1879 Marsh appointed C. disparate to the material obtained in Quarry 13 in the Morrison Formation. Also as C.amplus to the remains found by Arthur Lakes in quarry 1A. Some time later it was found that one of the pieces, a foot, belonged to an Allosaurus.
Between the 1880s and 1890s, the discoveries of new species called C. medius and C. nanus. Charles Gilmore also named C. browni and C. depressus when he redescribed in 1909 the specimens known through Marsh.
There was a redescription in 1980 of C. prestichi by Peter Galton and HP Powell. These determined that C. nanus, C. medius and C. Brown They were actually specimens of various stages of growth or specimens of different sexes of the C. disparatewhich validated it as a species.
In the same way a skull that Marsh assigned to C.amplus also belonged to C. disparate. Gilmore had also relied on this skull to describe that of Camptosaurus. However, Brill and Carpenter showed that it was not actually of this species. In 2007 it was assigned to the species Theiophytalia kerri.
In the case of C. depressus This was found in the Lakota Formation near Hot Springs, South Dakota. Charles Gilmore described it in 1909 based on a fragmentary postcranium that had a narrowness or depression in the Iliad.
In 2008 Carpenter and Wilson referred to this as P. Depressus Planicoxa. However, in 2010 McDonald and a group of collaborators demonstrated that the horizontal postacetabular process in C. depressus It was the result of a distortion. For that reason they assigned it to its own genus, the Osmakasaurus.
On the other hand the Camptosaurus aphanoecetes was named by Carpenter and Wilson in 2008. It differs from C. disparate in the jaw, in the short cervical vertebrae and in the straight ischium that ended in a small foot.
In 2010, Andrew McDonald and his collaborators understood that C. aphanoecetes which was related to advanced iguanodonts was transferred to the genus Uteodon.
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What does Camptosaurus mean?
Name Camptosaurus derives from Greek kamtos what does it mean curved and sauros what is lizard. In this way they refer to the flexibility of their vertebrae. The epithet disparate It is due to differences in proportion detected in some initial remains, which some time later were found to belong to another species of dinosaur.
The Anchylopollexia family
Camptosaurus, although it is mostly considered a member of the Iguanodontia, in modern phylogeny it is also placed as a basal member of the Anquilopollexia. The name of this clade translates as stiff thumbs.
The term comes from the Greek ankylos what is rigid or fused and from latin pollex What does it mean thumb. First described by Paul Sereno in 1986, its synapomorphic characteristic consisting of a conical thumb spine is a vital feature.
They were quite large specimens, whose weight could reach 8 tons, with a length of up to 15 meters. In 1986, Paul Sereno defined them as a clade consistent with the common ancestor of Camptosaurus, Parasalurlophus, and all its descendants.
In 2005 Sereno improved this definition by including two type species that were the Camptosaurus dispar and Parasaurolophus walkeri. He also considered them defined by a shared derived character which was the conical shaped thumbnail on the front paws.
Ankylopollexia is part of the ornithischian dinosaurs that existed between the end of the Jurassic and the end of the Cretaceous. It was a group derived from iguanodontid ornithopods that contained the Styracosterna subgroup.
Ankylopollexia appeared in the Jurassic, 156 million years ago, and thrived throughout the world during the Cretaceous. They are quite large compared to some carnivorous dinosaurs, although these generally had a herbivorous diet.
Its size varied greatly during its evolution. The Camptosaurus genus from the Jurassic was small and did not exceed 5.5 tons. The largest ankylopolexic was part of the hadrosaurs and was known as Shantungosaurus. It was almost 15 meters long and weighed up to 16 tons.
Early ankylopolexics tended to be smaller compared to the larger, more derived hadrosaurs. However, there were some exceptions in the Jurassic in Portugal, as is the case of the Styracosternan Iguanacolossus which was named for its distinctive sturdiness and size, which included 9 meters in length.
As for hadrosaurs, it is believed that one of their most basal members, the Bolong, could weigh around 200 kilos. Another exception was Tethyshadros, another genus in this group. Its weight was 350 kilograms and it existed only on some Italian islands. The call dwarfism of the islands possibly explained their small size.
Camptosaurus vs Iguanodon
It is quite easy to distinguish an ornithopod like Camptosaurus or Iguanodon from a sauropod. But differentiating between both families is complicated even for specialists.
Even today, orders and families are still exposed to continuous evaluation. Through continuous review, experts are closer every day to the true classification of the species. And this is valid even when there are doubtful or gray areas.
When it comes to Camptosaurus and Iguanodonts, there are small differences that have helped scientists recognize them. We must add the fact that fossil remains are often incomplete, something that further complicates the degree of difficulty in their classification.
These dinosaurs appear to belong to the same species when you look at their bones. They have the same profile and shape. Both are bipedal herbivores, with a beak and teeth. They also both have a tip on their thumb with which they defend themselves, or with which they look for food.
All this accounts for their close relationship in evolution. Although it is necessary to understand how close they are.
When you see them up close there are differences, but not many. For example, the Iguanodon had a prehensile finger that it would have used to obtain its food. With this it could have grabbed the limbs and approached to feed. Between the tip of the thumb and the prehensile little fingeriguanodonts had three webbed toes.
This was not what was happening with Camptosaurus. It was smaller in size than the Iguanodon. Its weight was around three tons, more than double that of Camptosaurus. This may be because the smaller Iguanodonts have been incorrectly classified as Camptosaurus.
More fossils in the future and a greater understanding of dinosaur evolution are needed to clear up the confusion between these species.
Camptosaurus Characteristics
The classification of Camptosaurus changed over the years. This allowed specialists to better understand its role in natural history. The following are its most notable peculiarities.
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Classification
Othniel Charles Marsh in 1885 assigned this dinosaur to his own family. That is to say to Camptosauridade. Over time the authors reassigned it as one of the initial members of the Iguanodontidae.
However, in modern phylogenetics it has been classified within the clade Ankylopollexia, of which it would be a basal member. Therefore the genus is closely related and more derived than the ancestor of hadrosaurids and iguanodontids such as Dryosaurus, Drinker and Othnielosaurus consors.
Description
Camptosaurus was small compared to the sauropods and ceratopsids of its time. However, he had a strong build and a volume that was between 800 and 900 kilos. Its length could reach almost 8 meters and it had a height of about 2 meters.
Its massive hind limbs allowed it to walk on two legs. Her legs had wide feet with four toes. And its short forelimbs were ossified, which was an evolutionary trait that developed over time. These also allowed it to support itself when feeding on its four legs.
Its skull was triangular and had a long, pointed snout, along with a beak instead of front teeth. This also placed it among the duck-billed dinosaurs. Its rows of teeth sat behind this beak and helped it grind fibrous plant material.
Feeding
It had teeth and a beak with which it could eat fibrous vegetables.. This beak was ideal for cutting cycads and other plant materials that it had to chew and digest. His cheeks were filled with hundreds of firm and durable teeth. They had to deal with very hard vegetation.
The fossil remains had ossified hands, on which they relied to consume the vegetation at ground level. The hands had a pointed thumb and spread fingers. It is possible that it could hold on to branches and small trees to carry food to its beak.
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Motion
Its movement was bipedal. He spent most of his time walking on two legs or running at speeds of 15 miles per hour. However, he also moved like a quadruped if the occasion warranted it.
However, it was slow and struggled when it stood on its four limbs, so it only used this form of locomotion while feeding on the ground.
His…