Hylaeosaurus ("forest lizard") was a nodosaurid ankylosaur from the Early Cretaceous of England. It was the third dinosaur to be named.
In The Land Before Time
Some Nodosaurs that may be Hylaeosaurus appear in The Land Before Time IV: Journey Through the Mists, in the crowd scene after the longneck herd arrives.
Hylaeosaurus also appears in the book The Land Before Time: How to Draw Dinosaurs as one of the dinosaurs that readers of the book can practice drawing.
- The character Rooter, from The Land Before Time was also proposed to be a Hylaeosaurus, but it is more likely he is based on reconstructions of Scolosaurus.