April 4, 2022 Scott Kraus

Camptosaurus was a Jurassic Herbivore

Camptosaurus was a small duck-billed dinosaur that lived during the Jurassic period from 156-145 million years ago. It roamed the forests on two legs, but had the option of prowling on four limbs for eating purposes. Camptosaurus has one of the most unique mouths of all dinosaurs, which uses both a beak and teeth for foraging. One of the earliest discovered hadrosaurs, Camptosaurus has been used as a model for classifying dinosaurs for over 100 years.

Quick Facts

About Camptosaurus

Camptosaurus (CAMP-toe-Sore-us) was a small, docile dinosaur that roamed the forests in the Jurassic Era. Its name is an interpretation from the first moniker it received, “Camptonotus”, which means “bent back” in Greek. Camptonotos was later named Camptosaurus. These dinosaurs were one of the few species to inhabit two continents, but some authorities list only North America as its habitat. This is because Camptosaurus and similar species blur the lines between what is a true Camptosurus of the Ornithischia order and what is an Iguanadon.

What Did Camptosaurus Look Like?

Although Camptosaurus was small in comparison to Sauropods and Ceratopsids of its time, it was still a heavily-built dinosaur—weighing in at around 2,000 pounds. It grew to lengths of 25 feet, but only reached about 6 feet in height.

It received its name because of the curved profile that gives Camptosaurus a bent look. It had massive hind limbs for bipedal movement. Its legs ended in broad, four-toed feet. The short forelimbs were ossified, which might have been an evolutionary trait developed over time, in order to support the creature while feeding on all fours. Camptosaurus had a triangular skull with a long, pointed snout and a beak instead of front teeth, thus gaining it entry into the duck-billed dinosaur classification. Rows of teeth sat behind the beak in order to grind fibrous vegetation.

What did Camptosaurus eat?

Camptosaurus had an herbivorous diet. Its teeth and beak were evolutionary traits that enabled it to eat fibrous vegetation. Camptosaurus’s beak was suited for sheering cycads and other prehistoric plant material for chewing and digestion. The cheeks of a Camptosaurus were filled with hundreds of durable teeth for grinding down the tough fibers. Recovered Camptosaurus teeth show wear consistent with the chewing of tough vegetation.

Fossil remains of Camptosaurus have ossified hands that would have allowed these grazers to move on all fours to feed on ground-level vegetation. The hands had a thumb spike and spreading fingers; therefore, it is possible that Camptosaurus was able to grab hold of limbs and small trees to pull food within reach of its beak.

How did Camptosaurus Move?

Camptosaurus was bipedal. It spent most of its time walking around on two legs or running at speeds of 15 miles per hour, but it could maneuver around on all fours if needed. Camptosaurus was slow and vulnerable on four limbs though, so this method of movement was probably only limited to feeding.

Camptosaurus received its name because research of the dinosaur’s backbone reveals a likelihood that it was flexible at the sacral vertebrae. The sacral vertebrae, which together create the sacrum, are located between the hip bones near the tail end of the spine. This flexibility would have allowed Camptosaurus to swivel at the hip, increasing its range of vision. The degree of flexibility is unknown, but the ability to rotate the back and neck would have made it difficult for a predator to sneak up on Camptosaurus.

Where did Camptosaurus live?

There are varying reports on the habitat of Camptosaurus. Some sources say that this genus roamed North America and Europe, while some say it lived in North America exclusively. These varying details may be because of the confusion over what species should be included in the genus. The first discovered species, which set the characteristics for the genus, was discovered in North America. Paoleontologists working in Europe added man species to the genus in the late 19^th and early 20^th centuries. There is no doubt about Camptosaurus’s presence in North America, but whether the species discovered in Europe was a Camptosaurus or not is still up for debate.

Experts predict that Camptosaurus was a forest dweller. Prehistoric forests would have supplied both the food and the shelter that Camptosaurus needed to survive. Its predators were much larger and lacked the agility need to catch a Camptosaurus in the woods.

The Discovery of Camptosaurus

The first Camptosaurus bones were found on September 4, 1879. William Reed was on an expedition in Albany County, Wyoming when he discovered the partial skeleton. One prominent part of the skeleton, the curved backbone, gave paleontologists a good idea of what Camptosaurus looked like when it was alive. The initial name was Camptonotus, Greek for “bent back”. In 1885, the fossil was renamed Camptosaurus when it was discover the Camptonotus was already being used to identify a species of cricket. All of the initial Camptosaurus discoveries took place in the Rocky Mountain area, west of the Western Interior Seaway that covered the Great Plains at the time. European scientists started uncovering hadrosaur-like dinosaurs around the turn of the century and classified a great number of their findings as species of Camptosaurus.

Camptosaurus vs. Iguanodon

It’s fairly easy, even for the average person, to distinguish an ornithopod such as Camptosaurus or Iguanodon from a sauropod, but distinguishing between families within the ornithopod suborder is a difficult task even for the experts. Orders and families are being re-evaluated as you read this. Through constant revision, paleontologists get closer to the truth of the matter, but for now there are some gray areas.

In the case of Camptosaurus and Iguanodon, there are little variances to help scientists distinguish a fossil. Add in the fact that fossil remains are often incomplete and the degree of difficulty involved in an accurate classification is compounded. To the untrained eye, these two separate dinosaurs look like the same species when the bones are observed. They have the same profile and shape. They are both bipedal herbivores with beaks and teeth. Both have a thumb spike for defense or foraging. These dinosaurs are definitely related, but how closely?

When you stop to take a look at the differences between these dinosaurs, you notice that there aren’t many. One distinct characteristic of the Iguanodon is a prehensile fifth finger that scientists hypothesize was used for foraging. This could have come in handy for grabbing limbs and pull them closer to feed. In-between the large thumb spike and the prehensile “pinky”, Iguanodons had three webbed fingers. This isn’t the case with Camptosaurus. In addition to these differences, Iguanodon was also much larger than Camptosaurus. Weight estimates come in at about three tons—more than twice the size of Camptosaurus. This may be because smaller Iguanodons have been incorrectly classified as Camptosaurus. Future fossils and a better understanding of dinosaur evolution is needed to clear up the confusion amongst species.

The Importance of Camptosaurus

Camptosaurus’s discovery has brought up numerous questions pertaining to its species and the closeness of relativity among other dinosaur species. Marsh assigned the Camptosaurus genus into a family of its own, Camptosauridae, but some contend it is an early member of Iguanodontidae. Some research has been completed that places Camptosaurus with clade Akylopollexia. As evolutionary research advances, it will become more apparent as to which species is in a family of its own and which is an amalgamation of an already established family of dinosaurs. For now however, we can simply hope to learn more about Camptosaurus and its close relatives from future discoveries and current research.