Hypsilophodon foxii HIP-sih-LOH-foh-don

"High-crested tooth"

Hypsilophodon silhouette
You 1.8 m (5.9 ft) tall
Hypsilophodon 2 m (6.6 ft) long
2 people holding hands
silhouette · Matthew Dempsey (CC-BY) via PhyloPic
Length
2 m (6.6 ft) — About 2 m long, ~20 kg — a fast bipedal herbivore the size of a small deer.
Period
Early Cretaceous (130–125 Mya)
Place
Europe · England · Isle of Wight
Food
Herbivore — Low-growing ferns and other soft plants, chewed quickly to escape predators.
Clade
Hypsilophodontidae Dinosauria Ornithischia Cerapoda Ornithopoda

Hypsilophodon was a small fast-running herbivore — built to flee. Long legs, light bones, big eyes for spotting trouble. For a long time scientists thought it lived in trees, but the foot anatomy turned out to be wrong for climbing. It was a ground runner, sprinting through the Early Cretaceous forests of southern England.

What we know

  • Small and lightly built — about deer-sized, all running anatomy.
  • Big eyes facing slightly forward, useful for spotting predators.
  • Once thought to be tree-climbing — that idea was abandoned in the 1970s.
  • Many skeletons known from the Isle of Wight in southern England.

What we guess

  • Whether it traveled in groups for protection — likely, based on multi-individual finds.
  • Top speed — bone strength models suggest 30–40 km/h.
  • Whether young Iguanodon and Hypsilophodon competed for the same plant food.