The Dryosaurus altus dinosaur is also known as tree lizard or oak lizard and was discovered by O. C. Marsh. The dinosaur fossil was first discovered in the late 19th century in the Western United States; and was subsequently fossils were also found in North America and Tanzania. It lived during the Late Jurassic period to the Early Cretaceous time range 156-145 million years ago. This bipedal dinosaur had a long neck, moderate to the small-sized skull, toothless upper jaw, short arms, and strong legs. Due to the lack of teeth in the upper jaw, it couldn't have hard or chewy food. It was a herbivorous dinosaur whose diet consisted of plants, leaves, conifers, and ginkgos. It could run very fast and was probably one of the fastest dinosaurs in the world.
The tree lizard called Dryosaurus is pronounced as 'dry - oh - sawr - rus'.
The Dryosaurus dinosaur or tree lizard is a bipedal herbivore that belongs to the Ornithopoda clade and Dryosauridae family.
The Dryosaurus altus lived on Earth during the Late Jurassic period ranging from 156-145 million years ago.
The Dryosaurus dinosaurs became extinct during the Late Cretaceous–Paleogene period mass extinction at the end of the Mesozoic Era around 66 million years ago when a large meteor or comet hit the earth.
Dryosaurus skeleton fossils were first discovered in the late 19th century by O. C. Marsh. They were found in Western United States (Colorado, Utah, and Wyoming), North America, and Tanzania.
The Dryosaurus lived in forest and woodland range with tall oak trees. The dinosaur got its name, oak lizard, from the habitat it lived in. It inhabited areas near water and with plenty of food.
Dryosaurus or tree lizards are herding dinosaurs that formed herds of around 20-30 dinosaurs. Their herds were a mix of Dryosaurus adults, juveniles, and some similarly sized dinosaur species. They form groups with larger armored herbivores for protection from carnivorous predators.
Dryosaurus lived for an average of around 14 years. Like other dinosaurs, they could have had three basic life stages; juvenile, sub-adult, and adult.
Dryosaurus reproduced by laying eggs. They were oviparous and the eggs were fertilized internally. Before mating, the males show their territory to the female and the female finally decides to stay in a place near water. They puff up their large cheeks with water during mating displays. Fossil of eggshells has also been found.
Dryosaurus had large eyes which allowed it to see predators or danger from far. They were bipedal dinosaurs with thin, long legs with three toes and shorter arms with five fingers. It had a moderate-sized head with a horny beak, toothless upper jaw, and cheek teeth which may have helped the dinosaur store food in its cheeks. It had a slender, long neck and a stiff tail used for balance, especially when it ran. Dryosaurus teeth had a distinct ridge on its lateral surface were characterized by a strong median ridge on the lateral surface.
The exact number of bones in a Dryosaurus is not known especially since an adult specimen has not been found yet. Many partial Dryosaurus skeleton fossils have been found ranging from embryonic to juvenile ages.
Like other dinosaurs, it can be assumed that the Dryosaurus dinosaur communicated using their bodies, slender limbs, cheeks, and vocalization. Dinosaurs can create distinct open-mouthed sounds and closed-mouthed sounds. The close-mouthed sounds of a lower frequency could travel long distances, which helped them communicate with the rest of the herd. They also puff up their cheeks with air during mating displays.
Dryosaurus size was estimated to be 24-36 in (60.96-91.44 cm) in length and 72 in (182.88 cm) tall. The exact length of an adult dinosaur is not known since an adult fossil has not been found in the world.
Dryosaurus altus species can move very fast. They can sprint at 50 mph (80.46 kph) and were probably some of the fastest dinosaurs of that world. It is almost as fast as a horse.
The weight of a Dryosaurus is 170-200 lb (77-90.7 kg). Its weight is six to seven times lighter than a Kodiak bear.
The males and females of this dinosaur species do not have any specific names. They are generally called female Dryosaurus and male Dryosaurus.
There are no particular names for the Dryosaurus dinosaur baby. The young dinosaurs are usually referred to as juveniles or babies.
Dryosaurus was a herbivore. Its diet consisted of leaves, plants, conifers, ginkgo, and fruits. It has teeth in both lower and upper jaws but lacked teeth on the front of the upper jaw.
The Dryosaurus dinosaur does not exhibit any aggressive behavior. They were usually in danger of being preyed on by carnivorous predators and thus lived in groups with large armored herbivores for protection. Their primary defense was their speed; if threatened or startled they would run away.
The genus name Dryosaurus is derived from the Greek 'drys' which means 'tree oak'. The species name altus means 'tall' in Latin. The dinosaur was named by O. C. Marsh.
Dryosaurus fossils showed that it followed craniofacial development growth patterns similar to other vertebrates. As juveniles, they had proportionally large eyes and proportionally short muzzles and as adults, their eyes became smaller and snout longer.
Dryosaurus was an ornithopod, whose intelligence is considered moderate among dinosaurs, but it had acute hearing and visual senses. The skull fossil had larger holes for the eyes and moderately sized hollows for the brain.
Yes, the female Dryosaurus dinosaur dug the ground. They placed their eggs underground and are covered by foliage. They use their beak to check the temperature of the eggs.
The Dryosaurus dinosaur was a bipedal dinosaur and was probably one of the fastest dinosaurs of its time. They used to sprint away from danger for covering short distances very quickly. They had three toes on their feet out of which two toes touched the ground when they walked on ran and its stiff tail helped maintain balance. They could run at 50 mph (80.46 kph) speed. The speed of the dinosaur is calculated from its leg biology and the fossils of its footsteps if available.
Here at Kidadl, we have carefully created lots of interesting family-friendly dinosaur facts for everyone to discover! Learn more about some other dinosaurs from our Indosaurus facts and Pegomastax facts pages.
You can even occupy yourself at home by coloring in one of our free printable Dryosaurus coloring pages.
Second image by Kordite.