About
Camptosaurus dispar was a robust herbivorous dinosaur that roamed the floodplains and forests of Late Jurassic North America alongside giants like Allosaurus, Diplodocus, and Stegosaurus. This medium-sized possessed a sturdy build with a relatively small head featuring a distinctive beak-like snout used for cropping vegetation. Its teeth were well-suited for grinding plant material, arranged in dental batteries that would become more sophisticated in its later descendants.
Capable of both and locomotion, Camptosaurus likely spent much of its time foraging on all fours but could rear up on its powerful hind legs to reach higher vegetation or flee from predators. Its forelimbs were notably robust with hoof-like digits, suggesting frequent use in walking. The hands retained some grasping ability, useful for pulling down branches.
First discovered by William Harlow Reed at Quarry 13 near Como Bluff, Wyoming, in 1879, Camptosaurus was named by Othniel Charles Marsh. The genus name references the flexibility observed in its vertebral column. Multiple specimens ranging from juveniles to adults have been recovered primarily from the Morrison Formation, making it one of the best-represented ornithopods of the Jurassic. As a basal member of the Ankylopollexia, Camptosaurus bridges the gap between small early ornithopods and the more derived iguanodonts of the Cretaceous, making it scientifically invaluable for understanding ornithopod evolution.
Explore the anatomy
5 featuresA tough, self-sharpening beak covered the front of the snout, perfect for snipping plants with precision. Wear marks on fossils suggest this dinosaur was a picky eater, choosing tough cycads and ferns over softer leaves.
Behind the beak sat rows of tightly packed, leaf-shaped teeth that worked together to grind up plants β an early version of the amazing tooth systems later duck-billed dinosaurs would have. CT scans show the replacement teeth weren't stacked as deep as in later species, making this an important evolutionary stepping stone.
The front legs were beefier than most plant-eaters of the Jurassic, with finger bones that had widened into mini hooves for walking on all fours. This setup hints at what was coming next in evolution β dinosaurs like Iguanodon that walked on their hands full-time.
The thigh bone was thick and strong, covered in rough patches where massive muscles once attached. These powerful legs could launch into fast sprints when predators like Allosaurus came calling β pretty impressive for a heavy-bodied herbivore!
The name Camptosaurus means "bent lizard," inspired by the curved, flexible spine scientists noticed in early fossils from Wyoming's famous Como Bluff. This bendy back probably helped when rearing up on two legs to munch on taller plants β a move backed up by fossils from babies to adults.
Where fossils were found

Morrison Formation
Colorado, Utah, Wyoming, Montana +6 more Β· United States
155β148 million years ago(7m year span)
Where Camptosaurus Roamed
During the Late Jurassic, Camptosaurus dispar roamed the lush floodplains and riverine forests of Laurasia, in a region that would become the Morrison Formation of western North Americaβa semi-arid landscape punctuated by seasonal rivers, fern prairies, and conifer woodlands, situated well inland from the retreating Sundance Sea to the north.
Keep exploring the vault

Allosaurus
Allosaurus fragilis
Allosaurus was the apex predator of the Morrison Formation and at 8.5m/1500kg would have easily preyed upon the smaller Camptosaurus (6m/785kg).

Oak Lizard
Dryosaurus altus
Both ornithopods from the Morrison Formation feeding on low to mid-level vegetation.

Iguanodon
Iguanodon bernissartensis
Camptosaurus is considered a basal member of Ankylopollexia, the clade containing Iguanodon.

Tenontosaurus
Tenontosaurus tilletti
Both represent medium-sized ornithopods that filled similar ecological roles as bulk-feeding herbivores in their respective ecosystems (Morrison vs.

Stegosaurus
Stegosaurus stenops
Both medium-sized herbivores co-occurring in the Morrison Formation, representing two dramatically different ornithischian survival strategies: Stegosaurus with plates and tail spikes for defense, Camptosaurus relying on alertness and herd behavior.

Diplodocus
Diplodocus carnegii
Co-occurring in the Morrison Formation, these herbivores occupied completely different feeding niches: Diplodocus browsed at extreme heights with its 25m length, while Camptosaurus fed on vegetation below 3 meters, demonstrating Morrison ecosystem stratification.
