Jurassic life. Computer artwork of a forest with prehistoric creatures that existed during the Jurassic Period (200 to 145 million years ago) in what is now North Yorkshire, England, UK. These include: a hypsilophodont (centre right) eating a plant, a dromaeosaur (feathered) chasing a coelurosaur in the water (upper left) and two gavials (crocodilians) on the far bank. The plants include horsetails, cycads, bennettitalians, and ginkgos.