Polacanthus foxii, a heavily armored dinosaur, roamed the Early Cretaceous period, around 130 million years ago. It featured a spiked back and tail, with a distinctive bony plate armor. Primarily a herbivore, it inhabited European floodplains, using its armored protection against predators.

Polacanthus foxii is a genus of ankylosaurian dinosaurs that lived during the Early Cretaceous period. Fossils of Polacanthus have primarily been found in the Wealden Group of England, specifically in the Isle of Wight and southern England. The geographical distribution of this species is limited to these regions in the United Kingdom, which were part of the European landmass during the Early Cretaceous.

During the Early Cretaceous, the environment of what is now southern England was characterized by a warm, subtropical climate with a mix of coastal plains and inland forests. The area was likely dominated by coniferous and cycad-like plants, with a significant presence of ferns and horsetails, indicative of lush vegetation. The climate would have supported a variety of plant-eating dinosaurs, including Polacanthus.

Polacanthus foxii occupied an ecological niche as a medium-sized herbivorous dinosaur, adapted to feeding on low-lying vegetation. Its body was protected by a series of bony plates and spikes, providing defense against predators. The species likely played a role in maintaining the balance of its ecosystem by grazing on plants and contributing to the plant-animal interaction dynamics of its habitat.