Hylaeosaurus is a genus of herbivorous dinosaur that lived during the early Cretaceous period, approximately 140 million years ago. It was discovered in what is now England and is known for its distinctive body structure, which included a robust build and a series of spikes along its back. This dinosaur is classified as a member of the group called ornithischians, which are characterized by their bird-like hips. Hylaeosaurus was about 5 to 6 meters long and likely walked on all fours. Its diet consisted mainly of plants, and it used its beak-like mouth to strip leaves and vegetation. The discovery of Hylaeosaurus contributed to the understanding of dinosaur diversity and evolution during the Cretaceous period.