The Hypsilophodon was a small Cretaceaus-age basal ornithopod that stood on its hind legs and stiff tail like a tripod. It was a zippy (and possibly armor-plated) herbivore that used its sharp front and flat back teeth to eat plants and tree branches. While small, it was fast, smart, and had plenty of ways to escape hungry predators.
Table of Contents
Some Quick Facts about the Hypsilophodon

Name | Hypsilophodon (meaning “high-crested tooth lizard” or “Hypsilophus-tooth lizard”) |
Type of dinosaur | Ornithopoda |
Territory | Forests and grasslands, England |
Size | Relatively small, 2 feet tall, 7.5 feet long |
Color | Gray/green with scaly, plated-armor |
Interesting Characteristics | Opposable fifth finger, sharp front teeth |
Diet | Plants, tree roots, seeds, and berries |
Major Threats | Meat-eating theropods |
Check out those teeth on that Hypsilophodon! With flat back teeth and sharp front teeth, this Cretaceous dino loved to dine on plants and tree branches in forested areas in England almost 125 million years ago.
What Type of Dinosaur is a Hypsilophodon?
The Hypsilophodon belongs to the Ornithopoda family of dinosaurs, similar to the Iguanodon. In fact, when the Hypsilophodon was first discovered, paleontologists believed it was a very small Iguanodon because it had a lot of similar characteristics but was much smaller.
As more fossil records were uncovered, a new species of ornithopod was born: the Hypsilophodon.
Ornithopods like the Hypsilophodon aren’t as flashy as their fellow meat-eating theropod cousins. Theropods were bipedal (they walked on their strong hind legs) and had small arms (like a T. rex).
What made the ornithopod dinosaur different is that their teeth were made for eating plants, and not meat. The Hypsilophodon had the speed and agility of a meat eater but the teeth of a vegetarian!
What Was Special About Hypsilophodon Teeth?
We can tell if a dinosaur was a carnivore or an herbivore based on the shape of its teeth. Sharp shark-like teeth are found on carnivores and are perfect for ripping into meat. Flat teeth are great for chewing on plants and are found on herbivores. What’s unique about the Hypsilophodon is that it had a little of both!
Now, it doesn’t necessarily mean that it’s an omnivore (or are both meat and plants). The Hypsilophodon had flat fan-shaped back teeth on its lower jaw but a sharp, pointed, high-ridged tooth.
Many scientists believe that the Hypsilophodon used its sharp front teeth to rip into more difficult-to-chew vegetation (like tree branches) rather than using it to eat meat. The unique teeth of the Hypsilophodon make it stand out from other Ornithopoda of its time!
Other discoveries were made in South Dakota, Romania, Spain, and Portugal. Most of the specimens were donated to the Natural History Museum in England.
How Big Was a Hypsilophodon?
The Hypsilophodon was surprisingly small and lightweight for a lower Cretaceous-age dino. In the early days of dinosaurs in the Triassic period, most dinosaurs were small. As time marched forward, dinosaurs got bigger and bigger. But not the Hypsilophodon.
Hypsilophodon was a small dino, about 2 feet tall (similar to Syntarsus) and 7.5 feet long. It weighed only 44 pounds, as much as a beagle. If we were to compare it with today’s animals, it was as tall as an average dog and a bit longer than iguana.
If you were to travel back in time and stumble upon a Hypsilophodon, it would be about as tall as an adult’s kneecap.
How did Hypsilophodon move?
This small dino was bipedal, meaning it was walking on its two hind legs. It was built for running. It had long light leg and a long stiff tail for balance and was a super fast dino.
How Did the Hypsilophodon Survive?

This ornithischian dinosaur had some pretty colossal predators lurking about in the early Cretaceous period. So, how could such a small dog-like dino survive such harsh conditions on Earth? Paleontologists have a few theories.
What makes the Hypsilophodon unique is its fifth finger, which is unusual for similar dinos of the time. Some researchers believe the Hypsilophodon used its extra digit to help it climb trees to escape from hungry predators. Imagine that: a dinosaur that can climb trees!
Some research also indicated that this dino was also equipped with armor plating, which would make its skin challenging to penetrate. However, most of these theories are constantly up for debate. Even today, paleontologists still argue about whether the Hypsilophodon had armor platings or if they could climb trees.
Where Were Hypsilophodon Fossils Found?
The fossils of the very first Hypsilophodon were discovered in 1849. They were among some of the first dino fossils on record (the first fossil discovered was the Megalosaurus in 1819). These original fossils date back to the Barremian age, nearly 125 million years ago. It was unearthed in England in a place now called the Mantell-Bowerbank in Wealden of the Isle of Wight.
At this sight, researchers discovered the ribs, parts of a pelvis, and pieces of thigh bones. Richard Owen described these bones as belonging to an Iguanadon, but he was mistaken. In 1867, Thomas Henry Huxley determined it was a new type of dinosaur – the Hypsilophodon.
The Isle of Wight (aka the Hypsilophodon bed) discovery wasn’t the only place these dinos roamed. Since the first discovery, even more fossil records of the Hypsilophodon have appeared all over the globe, although the highest concentrations are in England.