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. Here a feathered dromaeosaur (right) is chasing a coelurosaur (left) in a river surrounded by various plants including horsetails, cycads, bennettitalians, and ginkgos. On the far bank are two gavials (crocodilians).