Polacanthus ("Many Spikes") was a herbivorous ankylosaur dinosaur that grew 4 to 5 metres (13.1 to 16.5 ft) long. Polacanthus was distantly related to the much bigger Ankylosaurus, which, however, lived much later, was much larger than Polacanthus, and was an ankylosaurid.
Polacanthus lived during the Early Cretaceous period from (130-112) million years ago.
Polacanthus was a small-medium sized Ankylosaur, standing about 3 feet tall, was 4-5 meters (12-15) long and weighing over a ton (2000 lbs).
A lumbering, spiky plant-eater that accompanied herds of Iguanodon, these dinosaurs were among the smallest members of the ankylosaur family. Thesy were often found accompanying around Iguanodon herds, presumably, for mutual protection. Polacanthus also often gorged on conifers.